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drm/radeon/kms/r6xx+: voltage fixes
[linux-2.6/linux-acpi-2.6/ibm-acpi-2.6.git] / net / ipv4 / route.c
blob045f0ec6a4a02a257cd60760283cdd3fb8cd5fda
1 /*
2 * INET An implementation of the TCP/IP protocol suite for the LINUX
3 * operating system. INET is implemented using the BSD Socket
4 * interface as the means of communication with the user level.
5 *
6 * ROUTE - implementation of the IP router.
7 *
8 * Authors: Ross Biro
9 * Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
10 * Alan Cox, <gw4pts@gw4pts.ampr.org>
11 * Linus Torvalds, <Linus.Torvalds@helsinki.fi>
12 * Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
13 *
14 * Fixes:
15 * Alan Cox : Verify area fixes.
16 * Alan Cox : cli() protects routing changes
17 * Rui Oliveira : ICMP routing table updates
18 * (rco@di.uminho.pt) Routing table insertion and update
19 * Linus Torvalds : Rewrote bits to be sensible
20 * Alan Cox : Added BSD route gw semantics
21 * Alan Cox : Super /proc >4K
22 * Alan Cox : MTU in route table
23 * Alan Cox : MSS actually. Also added the window
24 * clamper.
25 * Sam Lantinga : Fixed route matching in rt_del()
26 * Alan Cox : Routing cache support.
27 * Alan Cox : Removed compatibility cruft.
28 * Alan Cox : RTF_REJECT support.
29 * Alan Cox : TCP irtt support.
30 * Jonathan Naylor : Added Metric support.
31 * Miquel van Smoorenburg : BSD API fixes.
32 * Miquel van Smoorenburg : Metrics.
33 * Alan Cox : Use __u32 properly
34 * Alan Cox : Aligned routing errors more closely with BSD
35 * our system is still very different.
36 * Alan Cox : Faster /proc handling
37 * Alexey Kuznetsov : Massive rework to support tree based routing,
38 * routing caches and better behaviour.
39 *
40 * Olaf Erb : irtt wasn't being copied right.
41 * Bjorn Ekwall : Kerneld route support.
42 * Alan Cox : Multicast fixed (I hope)
43 * Pavel Krauz : Limited broadcast fixed
44 * Mike McLagan : Routing by source
45 * Alexey Kuznetsov : End of old history. Split to fib.c and
46 * route.c and rewritten from scratch.
47 * Andi Kleen : Load-limit warning messages.
48 * Vitaly E. Lavrov : Transparent proxy revived after year coma.
49 * Vitaly E. Lavrov : Race condition in ip_route_input_slow.
50 * Tobias Ringstrom : Uninitialized res.type in ip_route_output_slow.
51 * Vladimir V. Ivanov : IP rule info (flowid) is really useful.
52 * Marc Boucher : routing by fwmark
53 * Robert Olsson : Added rt_cache statistics
54 * Arnaldo C. Melo : Convert proc stuff to seq_file
55 * Eric Dumazet : hashed spinlocks and rt_check_expire() fixes.
56 * Ilia Sotnikov : Ignore TOS on PMTUD and Redirect
57 * Ilia Sotnikov : Removed TOS from hash calculations
58 *
59 * This program is free software; you can redistribute it and/or
60 * modify it under the terms of the GNU General Public License
61 * as published by the Free Software Foundation; either version
62 * 2 of the License, or (at your option) any later version.
63 */
64
65 #include <linux/module.h>
66 #include <asm/uaccess.h>
67 #include <asm/system.h>
68 #include <linux/bitops.h>
69 #include <linux/types.h>
70 #include <linux/kernel.h>
71 #include <linux/mm.h>
72 #include <linux/bootmem.h>
73 #include <linux/string.h>
74 #include <linux/socket.h>
75 #include <linux/sockios.h>
76 #include <linux/errno.h>
77 #include <linux/in.h>
78 #include <linux/inet.h>
79 #include <linux/netdevice.h>
80 #include <linux/proc_fs.h>
81 #include <linux/init.h>
82 #include <linux/workqueue.h>
83 #include <linux/skbuff.h>
84 #include <linux/inetdevice.h>
85 #include <linux/igmp.h>
86 #include <linux/pkt_sched.h>
87 #include <linux/mroute.h>
88 #include <linux/netfilter_ipv4.h>
89 #include <linux/random.h>
90 #include <linux/jhash.h>
91 #include <linux/rcupdate.h>
92 #include <linux/times.h>
93 #include <linux/slab.h>
94 #include <net/dst.h>
95 #include <net/net_namespace.h>
96 #include <net/protocol.h>
97 #include <net/ip.h>
98 #include <net/route.h>
99 #include <net/inetpeer.h>
100 #include <net/sock.h>
101 #include <net/ip_fib.h>
102 #include <net/arp.h>
103 #include <net/tcp.h>
104 #include <net/icmp.h>
105 #include <net/xfrm.h>
106 #include <net/netevent.h>
107 #include <net/rtnetlink.h>
108 #ifdef CONFIG_SYSCTL
109 #include <linux/sysctl.h>
110 #endif
111
112 #define RT_FL_TOS(oldflp4) \
113 ((u32)(oldflp4->flowi4_tos & (IPTOS_RT_MASK | RTO_ONLINK)))
114
115 #define IP_MAX_MTU 0xFFF0
116
117 #define RT_GC_TIMEOUT (300*HZ)
118
119 static int ip_rt_max_size;
120 static int ip_rt_gc_timeout __read_mostly = RT_GC_TIMEOUT;
121 static int ip_rt_gc_interval __read_mostly = 60 * HZ;
122 static int ip_rt_gc_min_interval __read_mostly = HZ / 2;
123 static int ip_rt_redirect_number __read_mostly = 9;
124 static int ip_rt_redirect_load __read_mostly = HZ / 50;
125 static int ip_rt_redirect_silence __read_mostly = ((HZ / 50) << (9 + 1));
126 static int ip_rt_error_cost __read_mostly = HZ;
127 static int ip_rt_error_burst __read_mostly = 5 * HZ;
128 static int ip_rt_gc_elasticity __read_mostly = 8;
129 static int ip_rt_mtu_expires __read_mostly = 10 * 60 * HZ;
130 static int ip_rt_min_pmtu __read_mostly = 512 + 20 + 20;
131 static int ip_rt_min_advmss __read_mostly = 256;
132 static int rt_chain_length_max __read_mostly = 20;
133
134 /*
135 * Interface to generic destination cache.
136 */
137
138 static struct dst_entry *ipv4_dst_check(struct dst_entry *dst, u32 cookie);
139 static unsigned int ipv4_default_advmss(const struct dst_entry *dst);
140 static unsigned int ipv4_default_mtu(const struct dst_entry *dst);
141 static void ipv4_dst_destroy(struct dst_entry *dst);
142 static struct dst_entry *ipv4_negative_advice(struct dst_entry *dst);
143 static void ipv4_link_failure(struct sk_buff *skb);
144 static void ip_rt_update_pmtu(struct dst_entry *dst, u32 mtu);
145 static int rt_garbage_collect(struct dst_ops *ops);
146
147 static void ipv4_dst_ifdown(struct dst_entry *dst, struct net_device *dev,
148 int how)
149 {
150 }
151
152 static u32 *ipv4_cow_metrics(struct dst_entry *dst, unsigned long old)
153 {
154 struct rtable *rt = (struct rtable *) dst;
155 struct inet_peer *peer;
156 u32 *p = NULL;
157
158 if (!rt->peer)
159 rt_bind_peer(rt, rt->rt_dst, 1);
160
161 peer = rt->peer;
162 if (peer) {
163 u32 *old_p = __DST_METRICS_PTR(old);
164 unsigned long prev, new;
165
166 p = peer->metrics;
167 if (inet_metrics_new(peer))
168 memcpy(p, old_p, sizeof(u32) * RTAX_MAX);
169
170 new = (unsigned long) p;
171 prev = cmpxchg(&dst->_metrics, old, new);
172
173 if (prev != old) {
174 p = __DST_METRICS_PTR(prev);
175 if (prev & DST_METRICS_READ_ONLY)
176 p = NULL;
177 } else {
178 if (rt->fi) {
179 fib_info_put(rt->fi);
180 rt->fi = NULL;
181 }
182 }
183 }
184 return p;
185 }
186
187 static struct dst_ops ipv4_dst_ops = {
188 .family = AF_INET,
189 .protocol = cpu_to_be16(ETH_P_IP),
190 .gc = rt_garbage_collect,
191 .check = ipv4_dst_check,
192 .default_advmss = ipv4_default_advmss,
193 .default_mtu = ipv4_default_mtu,
194 .cow_metrics = ipv4_cow_metrics,
195 .destroy = ipv4_dst_destroy,
196 .ifdown = ipv4_dst_ifdown,
197 .negative_advice = ipv4_negative_advice,
198 .link_failure = ipv4_link_failure,
199 .update_pmtu = ip_rt_update_pmtu,
200 .local_out = __ip_local_out,
201 };
202
203 #define ECN_OR_COST(class) TC_PRIO_##class
204
205 const __u8 ip_tos2prio[16] = {
206 TC_PRIO_BESTEFFORT,
207 ECN_OR_COST(BESTEFFORT),
208 TC_PRIO_BESTEFFORT,
209 ECN_OR_COST(BESTEFFORT),
210 TC_PRIO_BULK,
211 ECN_OR_COST(BULK),
212 TC_PRIO_BULK,
213 ECN_OR_COST(BULK),
214 TC_PRIO_INTERACTIVE,
215 ECN_OR_COST(INTERACTIVE),
216 TC_PRIO_INTERACTIVE,
217 ECN_OR_COST(INTERACTIVE),
218 TC_PRIO_INTERACTIVE_BULK,
219 ECN_OR_COST(INTERACTIVE_BULK),
220 TC_PRIO_INTERACTIVE_BULK,
221 ECN_OR_COST(INTERACTIVE_BULK)
222 };
223
224
225 /*
226 * Route cache.
227 */
228
229 /* The locking scheme is rather straight forward:
230 *
231 * 1) Read-Copy Update protects the buckets of the central route hash.
232 * 2) Only writers remove entries, and they hold the lock
233 * as they look at rtable reference counts.
234 * 3) Only readers acquire references to rtable entries,
235 * they do so with atomic increments and with the
236 * lock held.
237 */
238
239 struct rt_hash_bucket {
240 struct rtable __rcu *chain;
241 };
242
243 #if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK) || \
244 defined(CONFIG_PROVE_LOCKING)
245 /*
246 * Instead of using one spinlock for each rt_hash_bucket, we use a table of spinlocks
247 * The size of this table is a power of two and depends on the number of CPUS.
248 * (on lockdep we have a quite big spinlock_t, so keep the size down there)
249 */
250 #ifdef CONFIG_LOCKDEP
251 # define RT_HASH_LOCK_SZ 256
252 #else
253 # if NR_CPUS >= 32
254 # define RT_HASH_LOCK_SZ 4096
255 # elif NR_CPUS >= 16
256 # define RT_HASH_LOCK_SZ 2048
257 # elif NR_CPUS >= 8
258 # define RT_HASH_LOCK_SZ 1024
259 # elif NR_CPUS >= 4
260 # define RT_HASH_LOCK_SZ 512
261 # else
262 # define RT_HASH_LOCK_SZ 256
263 # endif
264 #endif
265
266 static spinlock_t *rt_hash_locks;
267 # define rt_hash_lock_addr(slot) &rt_hash_locks[(slot) & (RT_HASH_LOCK_SZ - 1)]
268
269 static __init void rt_hash_lock_init(void)
270 {
271 int i;
272
273 rt_hash_locks = kmalloc(sizeof(spinlock_t) * RT_HASH_LOCK_SZ,
274 GFP_KERNEL);
275 if (!rt_hash_locks)
276 panic("IP: failed to allocate rt_hash_locks\n");
277
278 for (i = 0; i < RT_HASH_LOCK_SZ; i++)
279 spin_lock_init(&rt_hash_locks[i]);
280 }
281 #else
282 # define rt_hash_lock_addr(slot) NULL
283
284 static inline void rt_hash_lock_init(void)
285 {
286 }
287 #endif
288
289 static struct rt_hash_bucket *rt_hash_table __read_mostly;
290 static unsigned rt_hash_mask __read_mostly;
291 static unsigned int rt_hash_log __read_mostly;
292
293 static DEFINE_PER_CPU(struct rt_cache_stat, rt_cache_stat);
294 #define RT_CACHE_STAT_INC(field) __this_cpu_inc(rt_cache_stat.field)
295
296 static inline unsigned int rt_hash(__be32 daddr, __be32 saddr, int idx,
297 int genid)
298 {
299 return jhash_3words((__force u32)daddr, (__force u32)saddr,
300 idx, genid)
301 & rt_hash_mask;
302 }
303
304 static inline int rt_genid(struct net *net)
305 {
306 return atomic_read(&net->ipv4.rt_genid);
307 }
308
309 #ifdef CONFIG_PROC_FS
310 struct rt_cache_iter_state {
311 struct seq_net_private p;
312 int bucket;
313 int genid;
314 };
315
316 static struct rtable *rt_cache_get_first(struct seq_file *seq)
317 {
318 struct rt_cache_iter_state *st = seq->private;
319 struct rtable *r = NULL;
320
321 for (st->bucket = rt_hash_mask; st->bucket >= 0; --st->bucket) {
322 if (!rcu_dereference_raw(rt_hash_table[st->bucket].chain))
323 continue;
324 rcu_read_lock_bh();
325 r = rcu_dereference_bh(rt_hash_table[st->bucket].chain);
326 while (r) {
327 if (dev_net(r->dst.dev) == seq_file_net(seq) &&
328 r->rt_genid == st->genid)
329 return r;
330 r = rcu_dereference_bh(r->dst.rt_next);
331 }
332 rcu_read_unlock_bh();
333 }
334 return r;
335 }
336
337 static struct rtable *__rt_cache_get_next(struct seq_file *seq,
338 struct rtable *r)
339 {
340 struct rt_cache_iter_state *st = seq->private;
341
342 r = rcu_dereference_bh(r->dst.rt_next);
343 while (!r) {
344 rcu_read_unlock_bh();
345 do {
346 if (--st->bucket < 0)
347 return NULL;
348 } while (!rcu_dereference_raw(rt_hash_table[st->bucket].chain));
349 rcu_read_lock_bh();
350 r = rcu_dereference_bh(rt_hash_table[st->bucket].chain);
351 }
352 return r;
353 }
354
355 static struct rtable *rt_cache_get_next(struct seq_file *seq,
356 struct rtable *r)
357 {
358 struct rt_cache_iter_state *st = seq->private;
359 while ((r = __rt_cache_get_next(seq, r)) != NULL) {
360 if (dev_net(r->dst.dev) != seq_file_net(seq))
361 continue;
362 if (r->rt_genid == st->genid)
363 break;
364 }
365 return r;
366 }
367
368 static struct rtable *rt_cache_get_idx(struct seq_file *seq, loff_t pos)
369 {
370 struct rtable *r = rt_cache_get_first(seq);
371
372 if (r)
373 while (pos && (r = rt_cache_get_next(seq, r)))
374 --pos;
375 return pos ? NULL : r;
376 }
377
378 static void *rt_cache_seq_start(struct seq_file *seq, loff_t *pos)
379 {
380 struct rt_cache_iter_state *st = seq->private;
381 if (*pos)
382 return rt_cache_get_idx(seq, *pos - 1);
383 st->genid = rt_genid(seq_file_net(seq));
384 return SEQ_START_TOKEN;
385 }
386
387 static void *rt_cache_seq_next(struct seq_file *seq, void *v, loff_t *pos)
388 {
389 struct rtable *r;
390
391 if (v == SEQ_START_TOKEN)
392 r = rt_cache_get_first(seq);
393 else
394 r = rt_cache_get_next(seq, v);
395 ++*pos;
396 return r;
397 }
398
399 static void rt_cache_seq_stop(struct seq_file *seq, void *v)
400 {
401 if (v && v != SEQ_START_TOKEN)
402 rcu_read_unlock_bh();
403 }
404
405 static int rt_cache_seq_show(struct seq_file *seq, void *v)
406 {
407 if (v == SEQ_START_TOKEN)
408 seq_printf(seq, "%-127s\n",
409 "Iface\tDestination\tGateway \tFlags\t\tRefCnt\tUse\t"
410 "Metric\tSource\t\tMTU\tWindow\tIRTT\tTOS\tHHRef\t"
411 "HHUptod\tSpecDst");
412 else {
413 struct rtable *r = v;
414 int len;
415
416 seq_printf(seq, "%s\t%08X\t%08X\t%8X\t%d\t%u\t%d\t"
417 "%08X\t%d\t%u\t%u\t%02X\t%d\t%1d\t%08X%n",
418 r->dst.dev ? r->dst.dev->name : "*",
419 (__force u32)r->rt_dst,
420 (__force u32)r->rt_gateway,
421 r->rt_flags, atomic_read(&r->dst.__refcnt),
422 r->dst.__use, 0, (__force u32)r->rt_src,
423 dst_metric_advmss(&r->dst) + 40,
424 dst_metric(&r->dst, RTAX_WINDOW),
425 (int)((dst_metric(&r->dst, RTAX_RTT) >> 3) +
426 dst_metric(&r->dst, RTAX_RTTVAR)),
427 r->rt_key_tos,
428 r->dst.hh ? atomic_read(&r->dst.hh->hh_refcnt) : -1,
429 r->dst.hh ? (r->dst.hh->hh_output ==
430 dev_queue_xmit) : 0,
431 r->rt_spec_dst, &len);
432
433 seq_printf(seq, "%*s\n", 127 - len, "");
434 }
435 return 0;
436 }
437
438 static const struct seq_operations rt_cache_seq_ops = {
439 .start = rt_cache_seq_start,
440 .next = rt_cache_seq_next,
441 .stop = rt_cache_seq_stop,
442 .show = rt_cache_seq_show,
443 };
444
445 static int rt_cache_seq_open(struct inode *inode, struct file *file)
446 {
447 return seq_open_net(inode, file, &rt_cache_seq_ops,
448 sizeof(struct rt_cache_iter_state));
449 }
450
451 static const struct file_operations rt_cache_seq_fops = {
452 .owner = THIS_MODULE,
453 .open = rt_cache_seq_open,
454 .read = seq_read,
455 .llseek = seq_lseek,
456 .release = seq_release_net,
457 };
458
459
460 static void *rt_cpu_seq_start(struct seq_file *seq, loff_t *pos)
461 {
462 int cpu;
463
464 if (*pos == 0)
465 return SEQ_START_TOKEN;
466
467 for (cpu = *pos-1; cpu < nr_cpu_ids; ++cpu) {
468 if (!cpu_possible(cpu))
469 continue;
470 *pos = cpu+1;
471 return &per_cpu(rt_cache_stat, cpu);
472 }
473 return NULL;
474 }
475
476 static void *rt_cpu_seq_next(struct seq_file *seq, void *v, loff_t *pos)
477 {
478 int cpu;
479
480 for (cpu = *pos; cpu < nr_cpu_ids; ++cpu) {
481 if (!cpu_possible(cpu))
482 continue;
483 *pos = cpu+1;
484 return &per_cpu(rt_cache_stat, cpu);
485 }
486 return NULL;
487
488 }
489
490 static void rt_cpu_seq_stop(struct seq_file *seq, void *v)
491 {
492
493 }
494
495 static int rt_cpu_seq_show(struct seq_file *seq, void *v)
496 {
497 struct rt_cache_stat *st = v;
498
499 if (v == SEQ_START_TOKEN) {
500 seq_printf(seq, "entries in_hit in_slow_tot in_slow_mc in_no_route in_brd in_martian_dst in_martian_src out_hit out_slow_tot out_slow_mc gc_total gc_ignored gc_goal_miss gc_dst_overflow in_hlist_search out_hlist_search\n");
501 return 0;
502 }
503
504 seq_printf(seq,"%08x %08x %08x %08x %08x %08x %08x %08x "
505 " %08x %08x %08x %08x %08x %08x %08x %08x %08x \n",
506 dst_entries_get_slow(&ipv4_dst_ops),
507 st->in_hit,
508 st->in_slow_tot,
509 st->in_slow_mc,
510 st->in_no_route,
511 st->in_brd,
512 st->in_martian_dst,
513 st->in_martian_src,
514
515 st->out_hit,
516 st->out_slow_tot,
517 st->out_slow_mc,
518
519 st->gc_total,
520 st->gc_ignored,
521 st->gc_goal_miss,
522 st->gc_dst_overflow,
523 st->in_hlist_search,
524 st->out_hlist_search
525 );
526 return 0;
527 }
528
529 static const struct seq_operations rt_cpu_seq_ops = {
530 .start = rt_cpu_seq_start,
531 .next = rt_cpu_seq_next,
532 .stop = rt_cpu_seq_stop,
533 .show = rt_cpu_seq_show,
534 };
535
536
537 static int rt_cpu_seq_open(struct inode *inode, struct file *file)
538 {
539 return seq_open(file, &rt_cpu_seq_ops);
540 }
541
542 static const struct file_operations rt_cpu_seq_fops = {
543 .owner = THIS_MODULE,
544 .open = rt_cpu_seq_open,
545 .read = seq_read,
546 .llseek = seq_lseek,
547 .release = seq_release,
548 };
549
550 #ifdef CONFIG_IP_ROUTE_CLASSID
551 static int rt_acct_proc_show(struct seq_file *m, void *v)
552 {
553 struct ip_rt_acct *dst, *src;
554 unsigned int i, j;
555
556 dst = kcalloc(256, sizeof(struct ip_rt_acct), GFP_KERNEL);
557 if (!dst)
558 return -ENOMEM;
559
560 for_each_possible_cpu(i) {
561 src = (struct ip_rt_acct *)per_cpu_ptr(ip_rt_acct, i);
562 for (j = 0; j < 256; j++) {
563 dst[j].o_bytes += src[j].o_bytes;
564 dst[j].o_packets += src[j].o_packets;
565 dst[j].i_bytes += src[j].i_bytes;
566 dst[j].i_packets += src[j].i_packets;
567 }
568 }
569
570 seq_write(m, dst, 256 * sizeof(struct ip_rt_acct));
571 kfree(dst);
572 return 0;
573 }
574
575 static int rt_acct_proc_open(struct inode *inode, struct file *file)
576 {
577 return single_open(file, rt_acct_proc_show, NULL);
578 }
579
580 static const struct file_operations rt_acct_proc_fops = {
581 .owner = THIS_MODULE,
582 .open = rt_acct_proc_open,
583 .read = seq_read,
584 .llseek = seq_lseek,
585 .release = single_release,
586 };
587 #endif
588
589 static int __net_init ip_rt_do_proc_init(struct net *net)
590 {
591 struct proc_dir_entry *pde;
592
593 pde = proc_net_fops_create(net, "rt_cache", S_IRUGO,
594 &rt_cache_seq_fops);
595 if (!pde)
596 goto err1;
597
598 pde = proc_create("rt_cache", S_IRUGO,
599 net->proc_net_stat, &rt_cpu_seq_fops);
600 if (!pde)
601 goto err2;
602
603 #ifdef CONFIG_IP_ROUTE_CLASSID
604 pde = proc_create("rt_acct", 0, net->proc_net, &rt_acct_proc_fops);
605 if (!pde)
606 goto err3;
607 #endif
608 return 0;
609
610 #ifdef CONFIG_IP_ROUTE_CLASSID
611 err3:
612 remove_proc_entry("rt_cache", net->proc_net_stat);
613 #endif
614 err2:
615 remove_proc_entry("rt_cache", net->proc_net);
616 err1:
617 return -ENOMEM;
618 }
619
620 static void __net_exit ip_rt_do_proc_exit(struct net *net)
621 {
622 remove_proc_entry("rt_cache", net->proc_net_stat);
623 remove_proc_entry("rt_cache", net->proc_net);
624 #ifdef CONFIG_IP_ROUTE_CLASSID
625 remove_proc_entry("rt_acct", net->proc_net);
626 #endif
627 }
628
629 static struct pernet_operations ip_rt_proc_ops __net_initdata = {
630 .init = ip_rt_do_proc_init,
631 .exit = ip_rt_do_proc_exit,
632 };
633
634 static int __init ip_rt_proc_init(void)
635 {
636 return register_pernet_subsys(&ip_rt_proc_ops);
637 }
638
639 #else
640 static inline int ip_rt_proc_init(void)
641 {
642 return 0;
643 }
644 #endif /* CONFIG_PROC_FS */
645
646 static inline void rt_free(struct rtable *rt)
647 {
648 call_rcu_bh(&rt->dst.rcu_head, dst_rcu_free);
649 }
650
651 static inline void rt_drop(struct rtable *rt)
652 {
653 ip_rt_put(rt);
654 call_rcu_bh(&rt->dst.rcu_head, dst_rcu_free);
655 }
656
657 static inline int rt_fast_clean(struct rtable *rth)
658 {
659 /* Kill broadcast/multicast entries very aggresively, if they
660 collide in hash table with more useful entries */
661 return (rth->rt_flags & (RTCF_BROADCAST | RTCF_MULTICAST)) &&
662 rt_is_input_route(rth) && rth->dst.rt_next;
663 }
664
665 static inline int rt_valuable(struct rtable *rth)
666 {
667 return (rth->rt_flags & (RTCF_REDIRECTED | RTCF_NOTIFY)) ||
668 (rth->peer && rth->peer->pmtu_expires);
669 }
670
671 static int rt_may_expire(struct rtable *rth, unsigned long tmo1, unsigned long tmo2)
672 {
673 unsigned long age;
674 int ret = 0;
675
676 if (atomic_read(&rth->dst.__refcnt))
677 goto out;
678
679 age = jiffies - rth->dst.lastuse;
680 if ((age <= tmo1 && !rt_fast_clean(rth)) ||
681 (age <= tmo2 && rt_valuable(rth)))
682 goto out;
683 ret = 1;
684 out: return ret;
685 }
686
687 /* Bits of score are:
688 * 31: very valuable
689 * 30: not quite useless
690 * 29..0: usage counter
691 */
692 static inline u32 rt_score(struct rtable *rt)
693 {
694 u32 score = jiffies - rt->dst.lastuse;
695
696 score = ~score & ~(3<<30);
697
698 if (rt_valuable(rt))
699 score |= (1<<31);
700
701 if (rt_is_output_route(rt) ||
702 !(rt->rt_flags & (RTCF_BROADCAST|RTCF_MULTICAST|RTCF_LOCAL)))
703 score |= (1<<30);
704
705 return score;
706 }
707
708 static inline bool rt_caching(const struct net *net)
709 {
710 return net->ipv4.current_rt_cache_rebuild_count <=
711 net->ipv4.sysctl_rt_cache_rebuild_count;
712 }
713
714 static inline bool compare_hash_inputs(const struct rtable *rt1,
715 const struct rtable *rt2)
716 {
717 return ((((__force u32)rt1->rt_key_dst ^ (__force u32)rt2->rt_key_dst) |
718 ((__force u32)rt1->rt_key_src ^ (__force u32)rt2->rt_key_src) |
719 (rt1->rt_iif ^ rt2->rt_iif)) == 0);
720 }
721
722 static inline int compare_keys(struct rtable *rt1, struct rtable *rt2)
723 {
724 return (((__force u32)rt1->rt_key_dst ^ (__force u32)rt2->rt_key_dst) |
725 ((__force u32)rt1->rt_key_src ^ (__force u32)rt2->rt_key_src) |
726 (rt1->rt_mark ^ rt2->rt_mark) |
727 (rt1->rt_key_tos ^ rt2->rt_key_tos) |
728 (rt1->rt_oif ^ rt2->rt_oif) |
729 (rt1->rt_iif ^ rt2->rt_iif)) == 0;
730 }
731
732 static inline int compare_netns(struct rtable *rt1, struct rtable *rt2)
733 {
734 return net_eq(dev_net(rt1->dst.dev), dev_net(rt2->dst.dev));
735 }
736
737 static inline int rt_is_expired(struct rtable *rth)
738 {
739 return rth->rt_genid != rt_genid(dev_net(rth->dst.dev));
740 }
741
742 /*
743 * Perform a full scan of hash table and free all entries.
744 * Can be called by a softirq or a process.
745 * In the later case, we want to be reschedule if necessary
746 */
747 static void rt_do_flush(struct net *net, int process_context)
748 {
749 unsigned int i;
750 struct rtable *rth, *next;
751
752 for (i = 0; i <= rt_hash_mask; i++) {
753 struct rtable __rcu **pprev;
754 struct rtable *list;
755
756 if (process_context && need_resched())
757 cond_resched();
758 rth = rcu_dereference_raw(rt_hash_table[i].chain);
759 if (!rth)
760 continue;
761
762 spin_lock_bh(rt_hash_lock_addr(i));
763
764 list = NULL;
765 pprev = &rt_hash_table[i].chain;
766 rth = rcu_dereference_protected(*pprev,
767 lockdep_is_held(rt_hash_lock_addr(i)));
768
769 while (rth) {
770 next = rcu_dereference_protected(rth->dst.rt_next,
771 lockdep_is_held(rt_hash_lock_addr(i)));
772
773 if (!net ||
774 net_eq(dev_net(rth->dst.dev), net)) {
775 rcu_assign_pointer(*pprev, next);
776 rcu_assign_pointer(rth->dst.rt_next, list);
777 list = rth;
778 } else {
779 pprev = &rth->dst.rt_next;
780 }
781 rth = next;
782 }
783
784 spin_unlock_bh(rt_hash_lock_addr(i));
785
786 for (; list; list = next) {
787 next = rcu_dereference_protected(list->dst.rt_next, 1);
788 rt_free(list);
789 }
790 }
791 }
792
793 /*
794 * While freeing expired entries, we compute average chain length
795 * and standard deviation, using fixed-point arithmetic.
796 * This to have an estimation of rt_chain_length_max
797 * rt_chain_length_max = max(elasticity, AVG + 4*SD)
798 * We use 3 bits for frational part, and 29 (or 61) for magnitude.
799 */
800
801 #define FRACT_BITS 3
802 #define ONE (1UL << FRACT_BITS)
803
804 /*
805 * Given a hash chain and an item in this hash chain,
806 * find if a previous entry has the same hash_inputs
807 * (but differs on tos, mark or oif)
808 * Returns 0 if an alias is found.
809 * Returns ONE if rth has no alias before itself.
810 */
811 static int has_noalias(const struct rtable *head, const struct rtable *rth)
812 {
813 const struct rtable *aux = head;
814
815 while (aux != rth) {
816 if (compare_hash_inputs(aux, rth))
817 return 0;
818 aux = rcu_dereference_protected(aux->dst.rt_next, 1);
819 }
820 return ONE;
821 }
822
823 /*
824 * Perturbation of rt_genid by a small quantity [1..256]
825 * Using 8 bits of shuffling ensure we can call rt_cache_invalidate()
826 * many times (2^24) without giving recent rt_genid.
827 * Jenkins hash is strong enough that litle changes of rt_genid are OK.
828 */
829 static void rt_cache_invalidate(struct net *net)
830 {
831 unsigned char shuffle;
832
833 get_random_bytes(&shuffle, sizeof(shuffle));
834 atomic_add(shuffle + 1U, &net->ipv4.rt_genid);
835 }
836
837 /*
838 * delay < 0 : invalidate cache (fast : entries will be deleted later)
839 * delay >= 0 : invalidate & flush cache (can be long)
840 */
841 void rt_cache_flush(struct net *net, int delay)
842 {
843 rt_cache_invalidate(net);
844 if (delay >= 0)
845 rt_do_flush(net, !in_softirq());
846 }
847
848 /* Flush previous cache invalidated entries from the cache */
849 void rt_cache_flush_batch(struct net *net)
850 {
851 rt_do_flush(net, !in_softirq());
852 }
853
854 static void rt_emergency_hash_rebuild(struct net *net)
855 {
856 if (net_ratelimit())
857 printk(KERN_WARNING "Route hash chain too long!\n");
858 rt_cache_invalidate(net);
859 }
860
861 /*
862 Short description of GC goals.
863
864 We want to build algorithm, which will keep routing cache
865 at some equilibrium point, when number of aged off entries
866 is kept approximately equal to newly generated ones.
867
868 Current expiration strength is variable "expire".
869 We try to adjust it dynamically, so that if networking
870 is idle expires is large enough to keep enough of warm entries,
871 and when load increases it reduces to limit cache size.
872 */
873
874 static int rt_garbage_collect(struct dst_ops *ops)
875 {
876 static unsigned long expire = RT_GC_TIMEOUT;
877 static unsigned long last_gc;
878 static int rover;
879 static int equilibrium;
880 struct rtable *rth;
881 struct rtable __rcu **rthp;
882 unsigned long now = jiffies;
883 int goal;
884 int entries = dst_entries_get_fast(&ipv4_dst_ops);
885
886 /*
887 * Garbage collection is pretty expensive,
888 * do not make it too frequently.
889 */
890
891 RT_CACHE_STAT_INC(gc_total);
892
893 if (now - last_gc < ip_rt_gc_min_interval &&
894 entries < ip_rt_max_size) {
895 RT_CACHE_STAT_INC(gc_ignored);
896 goto out;
897 }
898
899 entries = dst_entries_get_slow(&ipv4_dst_ops);
900 /* Calculate number of entries, which we want to expire now. */
901 goal = entries - (ip_rt_gc_elasticity << rt_hash_log);
902 if (goal <= 0) {
903 if (equilibrium < ipv4_dst_ops.gc_thresh)
904 equilibrium = ipv4_dst_ops.gc_thresh;
905 goal = entries - equilibrium;
906 if (goal > 0) {
907 equilibrium += min_t(unsigned int, goal >> 1, rt_hash_mask + 1);
908 goal = entries - equilibrium;
909 }
910 } else {
911 /* We are in dangerous area. Try to reduce cache really
912 * aggressively.
913 */
914 goal = max_t(unsigned int, goal >> 1, rt_hash_mask + 1);
915 equilibrium = entries - goal;
916 }
917
918 if (now - last_gc >= ip_rt_gc_min_interval)
919 last_gc = now;
920
921 if (goal <= 0) {
922 equilibrium += goal;
923 goto work_done;
924 }
925
926 do {
927 int i, k;
928
929 for (i = rt_hash_mask, k = rover; i >= 0; i--) {
930 unsigned long tmo = expire;
931
932 k = (k + 1) & rt_hash_mask;
933 rthp = &rt_hash_table[k].chain;
934 spin_lock_bh(rt_hash_lock_addr(k));
935 while ((rth = rcu_dereference_protected(*rthp,
936 lockdep_is_held(rt_hash_lock_addr(k)))) != NULL) {
937 if (!rt_is_expired(rth) &&
938 !rt_may_expire(rth, tmo, expire)) {
939 tmo >>= 1;
940 rthp = &rth->dst.rt_next;
941 continue;
942 }
943 *rthp = rth->dst.rt_next;
944 rt_free(rth);
945 goal--;
946 }
947 spin_unlock_bh(rt_hash_lock_addr(k));
948 if (goal <= 0)
949 break;
950 }
951 rover = k;
952
953 if (goal <= 0)
954 goto work_done;
955
956 /* Goal is not achieved. We stop process if:
957
958 - if expire reduced to zero. Otherwise, expire is halfed.
959 - if table is not full.
960 - if we are called from interrupt.
961 - jiffies check is just fallback/debug loop breaker.
962 We will not spin here for long time in any case.
963 */
964
965 RT_CACHE_STAT_INC(gc_goal_miss);
966
967 if (expire == 0)
968 break;
969
970 expire >>= 1;
971
972 if (dst_entries_get_fast(&ipv4_dst_ops) < ip_rt_max_size)
973 goto out;
974 } while (!in_softirq() && time_before_eq(jiffies, now));
975
976 if (dst_entries_get_fast(&ipv4_dst_ops) < ip_rt_max_size)
977 goto out;
978 if (dst_entries_get_slow(&ipv4_dst_ops) < ip_rt_max_size)
979 goto out;
980 if (net_ratelimit())
981 printk(KERN_WARNING "dst cache overflow\n");
982 RT_CACHE_STAT_INC(gc_dst_overflow);
983 return 1;
984
985 work_done:
986 expire += ip_rt_gc_min_interval;
987 if (expire > ip_rt_gc_timeout ||
988 dst_entries_get_fast(&ipv4_dst_ops) < ipv4_dst_ops.gc_thresh ||
989 dst_entries_get_slow(&ipv4_dst_ops) < ipv4_dst_ops.gc_thresh)
990 expire = ip_rt_gc_timeout;
991 out: return 0;
992 }
993
994 /*
995 * Returns number of entries in a hash chain that have different hash_inputs
996 */
997 static int slow_chain_length(const struct rtable *head)
998 {
999 int length = 0;
1000 const struct rtable *rth = head;
1001
1002 while (rth) {
1003 length += has_noalias(head, rth);
1004 rth = rcu_dereference_protected(rth->dst.rt_next, 1);
1005 }
1006 return length >> FRACT_BITS;
1007 }
1008
1009 static struct rtable *rt_intern_hash(unsigned hash, struct rtable *rt,
1010 struct sk_buff *skb, int ifindex)
1011 {
1012 struct rtable *rth, *cand;
1013 struct rtable __rcu **rthp, **candp;
1014 unsigned long now;
1015 u32 min_score;
1016 int chain_length;
1017 int attempts = !in_softirq();
1018
1019 restart:
1020 chain_length = 0;
1021 min_score = ~(u32)0;
1022 cand = NULL;
1023 candp = NULL;
1024 now = jiffies;
1025
1026 if (!rt_caching(dev_net(rt->dst.dev))) {
1027 /*
1028 * If we're not caching, just tell the caller we
1029 * were successful and don't touch the route. The
1030 * caller hold the sole reference to the cache entry, and
1031 * it will be released when the caller is done with it.
1032 * If we drop it here, the callers have no way to resolve routes
1033 * when we're not caching. Instead, just point *rp at rt, so
1034 * the caller gets a single use out of the route
1035 * Note that we do rt_free on this new route entry, so that
1036 * once its refcount hits zero, we are still able to reap it
1037 * (Thanks Alexey)
1038 * Note: To avoid expensive rcu stuff for this uncached dst,
1039 * we set DST_NOCACHE so that dst_release() can free dst without
1040 * waiting a grace period.
1041 */
1042
1043 rt->dst.flags |= DST_NOCACHE;
1044 if (rt->rt_type == RTN_UNICAST || rt_is_output_route(rt)) {
1045 int err = arp_bind_neighbour(&rt->dst);
1046 if (err) {
1047 if (net_ratelimit())
1048 printk(KERN_WARNING
1049 "Neighbour table failure & not caching routes.\n");
1050 ip_rt_put(rt);
1051 return ERR_PTR(err);
1052 }
1053 }
1054
1055 goto skip_hashing;
1056 }
1057
1058 rthp = &rt_hash_table[hash].chain;
1059
1060 spin_lock_bh(rt_hash_lock_addr(hash));
1061 while ((rth = rcu_dereference_protected(*rthp,
1062 lockdep_is_held(rt_hash_lock_addr(hash)))) != NULL) {
1063 if (rt_is_expired(rth)) {
1064 *rthp = rth->dst.rt_next;
1065 rt_free(rth);
1066 continue;
1067 }
1068 if (compare_keys(rth, rt) && compare_netns(rth, rt)) {
1069 /* Put it first */
1070 *rthp = rth->dst.rt_next;
1071 /*
1072 * Since lookup is lockfree, the deletion
1073 * must be visible to another weakly ordered CPU before
1074 * the insertion at the start of the hash chain.
1075 */
1076 rcu_assign_pointer(rth->dst.rt_next,
1077 rt_hash_table[hash].chain);
1078 /*
1079 * Since lookup is lockfree, the update writes
1080 * must be ordered for consistency on SMP.
1081 */
1082 rcu_assign_pointer(rt_hash_table[hash].chain, rth);
1083
1084 dst_use(&rth->dst, now);
1085 spin_unlock_bh(rt_hash_lock_addr(hash));
1086
1087 rt_drop(rt);
1088 if (skb)
1089 skb_dst_set(skb, &rth->dst);
1090 return rth;
1091 }
1092
1093 if (!atomic_read(&rth->dst.__refcnt)) {
1094 u32 score = rt_score(rth);
1095
1096 if (score <= min_score) {
1097 cand = rth;
1098 candp = rthp;
1099 min_score = score;
1100 }
1101 }
1102
1103 chain_length++;
1104
1105 rthp = &rth->dst.rt_next;
1106 }
1107
1108 if (cand) {
1109 /* ip_rt_gc_elasticity used to be average length of chain
1110 * length, when exceeded gc becomes really aggressive.
1111 *
1112 * The second limit is less certain. At the moment it allows
1113 * only 2 entries per bucket. We will see.
1114 */
1115 if (chain_length > ip_rt_gc_elasticity) {
1116 *candp = cand->dst.rt_next;
1117 rt_free(cand);
1118 }
1119 } else {
1120 if (chain_length > rt_chain_length_max &&
1121 slow_chain_length(rt_hash_table[hash].chain) > rt_chain_length_max) {
1122 struct net *net = dev_net(rt->dst.dev);
1123 int num = ++net->ipv4.current_rt_cache_rebuild_count;
1124 if (!rt_caching(net)) {
1125 printk(KERN_WARNING "%s: %d rebuilds is over limit, route caching disabled\n",
1126 rt->dst.dev->name, num);
1127 }
1128 rt_emergency_hash_rebuild(net);
1129 spin_unlock_bh(rt_hash_lock_addr(hash));
1130
1131 hash = rt_hash(rt->rt_key_dst, rt->rt_key_src,
1132 ifindex, rt_genid(net));
1133 goto restart;
1134 }
1135 }
1136
1137 /* Try to bind route to arp only if it is output
1138 route or unicast forwarding path.
1139 */
1140 if (rt->rt_type == RTN_UNICAST || rt_is_output_route(rt)) {
1141 int err = arp_bind_neighbour(&rt->dst);
1142 if (err) {
1143 spin_unlock_bh(rt_hash_lock_addr(hash));
1144
1145 if (err != -ENOBUFS) {
1146 rt_drop(rt);
1147 return ERR_PTR(err);
1148 }
1149
1150 /* Neighbour tables are full and nothing
1151 can be released. Try to shrink route cache,
1152 it is most likely it holds some neighbour records.
1153 */
1154 if (attempts-- > 0) {
1155 int saved_elasticity = ip_rt_gc_elasticity;
1156 int saved_int = ip_rt_gc_min_interval;
1157 ip_rt_gc_elasticity = 1;
1158 ip_rt_gc_min_interval = 0;
1159 rt_garbage_collect(&ipv4_dst_ops);
1160 ip_rt_gc_min_interval = saved_int;
1161 ip_rt_gc_elasticity = saved_elasticity;
1162 goto restart;
1163 }
1164
1165 if (net_ratelimit())
1166 printk(KERN_WARNING "ipv4: Neighbour table overflow.\n");
1167 rt_drop(rt);
1168 return ERR_PTR(-ENOBUFS);
1169 }
1170 }
1171
1172 rt->dst.rt_next = rt_hash_table[hash].chain;
1173
1174 /*
1175 * Since lookup is lockfree, we must make sure
1176 * previous writes to rt are committed to memory
1177 * before making rt visible to other CPUS.
1178 */
1179 rcu_assign_pointer(rt_hash_table[hash].chain, rt);
1180
1181 spin_unlock_bh(rt_hash_lock_addr(hash));
1182
1183 skip_hashing:
1184 if (skb)
1185 skb_dst_set(skb, &rt->dst);
1186 return rt;
1187 }
1188
1189 static atomic_t __rt_peer_genid = ATOMIC_INIT(0);
1190
1191 static u32 rt_peer_genid(void)
1192 {
1193 return atomic_read(&__rt_peer_genid);
1194 }
1195
1196 void rt_bind_peer(struct rtable *rt, __be32 daddr, int create)
1197 {
1198 struct inet_peer *peer;
1199
1200 peer = inet_getpeer_v4(daddr, create);
1201
1202 if (peer && cmpxchg(&rt->peer, NULL, peer) != NULL)
1203 inet_putpeer(peer);
1204 else
1205 rt->rt_peer_genid = rt_peer_genid();
1206 }
1207
1208 /*
1209 * Peer allocation may fail only in serious out-of-memory conditions. However
1210 * we still can generate some output.
1211 * Random ID selection looks a bit dangerous because we have no chances to
1212 * select ID being unique in a reasonable period of time.
1213 * But broken packet identifier may be better than no packet at all.
1214 */
1215 static void ip_select_fb_ident(struct iphdr *iph)
1216 {
1217 static DEFINE_SPINLOCK(ip_fb_id_lock);
1218 static u32 ip_fallback_id;
1219 u32 salt;
1220
1221 spin_lock_bh(&ip_fb_id_lock);
1222 salt = secure_ip_id((__force __be32)ip_fallback_id ^ iph->daddr);
1223 iph->id = htons(salt & 0xFFFF);
1224 ip_fallback_id = salt;
1225 spin_unlock_bh(&ip_fb_id_lock);
1226 }
1227
1228 void __ip_select_ident(struct iphdr *iph, struct dst_entry *dst, int more)
1229 {
1230 struct rtable *rt = (struct rtable *) dst;
1231
1232 if (rt) {
1233 if (rt->peer == NULL)
1234 rt_bind_peer(rt, rt->rt_dst, 1);
1235
1236 /* If peer is attached to destination, it is never detached,
1237 so that we need not to grab a lock to dereference it.
1238 */
1239 if (rt->peer) {
1240 iph->id = htons(inet_getid(rt->peer, more));
1241 return;
1242 }
1243 } else
1244 printk(KERN_DEBUG "rt_bind_peer(0) @%p\n",
1245 __builtin_return_address(0));
1246
1247 ip_select_fb_ident(iph);
1248 }
1249 EXPORT_SYMBOL(__ip_select_ident);
1250
1251 static void rt_del(unsigned hash, struct rtable *rt)
1252 {
1253 struct rtable __rcu **rthp;
1254 struct rtable *aux;
1255
1256 rthp = &rt_hash_table[hash].chain;
1257 spin_lock_bh(rt_hash_lock_addr(hash));
1258 ip_rt_put(rt);
1259 while ((aux = rcu_dereference_protected(*rthp,
1260 lockdep_is_held(rt_hash_lock_addr(hash)))) != NULL) {
1261 if (aux == rt || rt_is_expired(aux)) {
1262 *rthp = aux->dst.rt_next;
1263 rt_free(aux);
1264 continue;
1265 }
1266 rthp = &aux->dst.rt_next;
1267 }
1268 spin_unlock_bh(rt_hash_lock_addr(hash));
1269 }
1270
1271 /* called in rcu_read_lock() section */
1272 void ip_rt_redirect(__be32 old_gw, __be32 daddr, __be32 new_gw,
1273 __be32 saddr, struct net_device *dev)
1274 {
1275 struct in_device *in_dev = __in_dev_get_rcu(dev);
1276 struct inet_peer *peer;
1277 struct net *net;
1278
1279 if (!in_dev)
1280 return;
1281
1282 net = dev_net(dev);
1283 if (new_gw == old_gw || !IN_DEV_RX_REDIRECTS(in_dev) ||
1284 ipv4_is_multicast(new_gw) || ipv4_is_lbcast(new_gw) ||
1285 ipv4_is_zeronet(new_gw))
1286 goto reject_redirect;
1287
1288 if (!IN_DEV_SHARED_MEDIA(in_dev)) {
1289 if (!inet_addr_onlink(in_dev, new_gw, old_gw))
1290 goto reject_redirect;
1291 if (IN_DEV_SEC_REDIRECTS(in_dev) && ip_fib_check_default(new_gw, dev))
1292 goto reject_redirect;
1293 } else {
1294 if (inet_addr_type(net, new_gw) != RTN_UNICAST)
1295 goto reject_redirect;
1296 }
1297
1298 peer = inet_getpeer_v4(daddr, 1);
1299 if (peer) {
1300 peer->redirect_learned.a4 = new_gw;
1301
1302 inet_putpeer(peer);
1303
1304 atomic_inc(&__rt_peer_genid);
1305 }
1306 return;
1307
1308 reject_redirect:
1309 #ifdef CONFIG_IP_ROUTE_VERBOSE
1310 if (IN_DEV_LOG_MARTIANS(in_dev) && net_ratelimit())
1311 printk(KERN_INFO "Redirect from %pI4 on %s about %pI4 ignored.\n"
1312 " Advised path = %pI4 -> %pI4\n",
1313 &old_gw, dev->name, &new_gw,
1314 &saddr, &daddr);
1315 #endif
1316 ;
1317 }
1318
1319 static bool peer_pmtu_expired(struct inet_peer *peer)
1320 {
1321 unsigned long orig = ACCESS_ONCE(peer->pmtu_expires);
1322
1323 return orig &&
1324 time_after_eq(jiffies, orig) &&
1325 cmpxchg(&peer->pmtu_expires, orig, 0) == orig;
1326 }
1327
1328 static bool peer_pmtu_cleaned(struct inet_peer *peer)
1329 {
1330 unsigned long orig = ACCESS_ONCE(peer->pmtu_expires);
1331
1332 return orig &&
1333 cmpxchg(&peer->pmtu_expires, orig, 0) == orig;
1334 }
1335
1336 static struct dst_entry *ipv4_negative_advice(struct dst_entry *dst)
1337 {
1338 struct rtable *rt = (struct rtable *)dst;
1339 struct dst_entry *ret = dst;
1340
1341 if (rt) {
1342 if (dst->obsolete > 0) {
1343 ip_rt_put(rt);
1344 ret = NULL;
1345 } else if (rt->rt_flags & RTCF_REDIRECTED) {
1346 unsigned hash = rt_hash(rt->rt_key_dst, rt->rt_key_src,
1347 rt->rt_oif,
1348 rt_genid(dev_net(dst->dev)));
1349 rt_del(hash, rt);
1350 ret = NULL;
1351 } else if (rt->peer && peer_pmtu_expired(rt->peer)) {
1352 dst_metric_set(dst, RTAX_MTU, rt->peer->pmtu_orig);
1353 }
1354 }
1355 return ret;
1356 }
1357
1358 /*
1359 * Algorithm:
1360 * 1. The first ip_rt_redirect_number redirects are sent
1361 * with exponential backoff, then we stop sending them at all,
1362 * assuming that the host ignores our redirects.
1363 * 2. If we did not see packets requiring redirects
1364 * during ip_rt_redirect_silence, we assume that the host
1365 * forgot redirected route and start to send redirects again.
1366 *
1367 * This algorithm is much cheaper and more intelligent than dumb load limiting
1368 * in icmp.c.
1369 *
1370 * NOTE. Do not forget to inhibit load limiting for redirects (redundant)
1371 * and "frag. need" (breaks PMTU discovery) in icmp.c.
1372 */
1373
1374 void ip_rt_send_redirect(struct sk_buff *skb)
1375 {
1376 struct rtable *rt = skb_rtable(skb);
1377 struct in_device *in_dev;
1378 struct inet_peer *peer;
1379 int log_martians;
1380
1381 rcu_read_lock();
1382 in_dev = __in_dev_get_rcu(rt->dst.dev);
1383 if (!in_dev || !IN_DEV_TX_REDIRECTS(in_dev)) {
1384 rcu_read_unlock();
1385 return;
1386 }
1387 log_martians = IN_DEV_LOG_MARTIANS(in_dev);
1388 rcu_read_unlock();
1389
1390 if (!rt->peer)
1391 rt_bind_peer(rt, rt->rt_dst, 1);
1392 peer = rt->peer;
1393 if (!peer) {
1394 icmp_send(skb, ICMP_REDIRECT, ICMP_REDIR_HOST, rt->rt_gateway);
1395 return;
1396 }
1397
1398 /* No redirected packets during ip_rt_redirect_silence;
1399 * reset the algorithm.
1400 */
1401 if (time_after(jiffies, peer->rate_last + ip_rt_redirect_silence))
1402 peer->rate_tokens = 0;
1403
1404 /* Too many ignored redirects; do not send anything
1405 * set dst.rate_last to the last seen redirected packet.
1406 */
1407 if (peer->rate_tokens >= ip_rt_redirect_number) {
1408 peer->rate_last = jiffies;
1409 return;
1410 }
1411
1412 /* Check for load limit; set rate_last to the latest sent
1413 * redirect.
1414 */
1415 if (peer->rate_tokens == 0 ||
1416 time_after(jiffies,
1417 (peer->rate_last +
1418 (ip_rt_redirect_load << peer->rate_tokens)))) {
1419 icmp_send(skb, ICMP_REDIRECT, ICMP_REDIR_HOST, rt->rt_gateway);
1420 peer->rate_last = jiffies;
1421 ++peer->rate_tokens;
1422 #ifdef CONFIG_IP_ROUTE_VERBOSE
1423 if (log_martians &&
1424 peer->rate_tokens == ip_rt_redirect_number &&
1425 net_ratelimit())
1426 printk(KERN_WARNING "host %pI4/if%d ignores redirects for %pI4 to %pI4.\n",
1427 &ip_hdr(skb)->saddr, rt->rt_iif,
1428 &rt->rt_dst, &rt->rt_gateway);
1429 #endif
1430 }
1431 }
1432
1433 static int ip_error(struct sk_buff *skb)
1434 {
1435 struct rtable *rt = skb_rtable(skb);
1436 struct inet_peer *peer;
1437 unsigned long now;
1438 bool send;
1439 int code;
1440
1441 switch (rt->dst.error) {
1442 case EINVAL:
1443 default:
1444 goto out;
1445 case EHOSTUNREACH:
1446 code = ICMP_HOST_UNREACH;
1447 break;
1448 case ENETUNREACH:
1449 code = ICMP_NET_UNREACH;
1450 IP_INC_STATS_BH(dev_net(rt->dst.dev),
1451 IPSTATS_MIB_INNOROUTES);
1452 break;
1453 case EACCES:
1454 code = ICMP_PKT_FILTERED;
1455 break;
1456 }
1457
1458 if (!rt->peer)
1459 rt_bind_peer(rt, rt->rt_dst, 1);
1460 peer = rt->peer;
1461
1462 send = true;
1463 if (peer) {
1464 now = jiffies;
1465 peer->rate_tokens += now - peer->rate_last;
1466 if (peer->rate_tokens > ip_rt_error_burst)
1467 peer->rate_tokens = ip_rt_error_burst;
1468 peer->rate_last = now;
1469 if (peer->rate_tokens >= ip_rt_error_cost)
1470 peer->rate_tokens -= ip_rt_error_cost;
1471 else
1472 send = false;
1473 }
1474 if (send)
1475 icmp_send(skb, ICMP_DEST_UNREACH, code, 0);
1476
1477 out: kfree_skb(skb);
1478 return 0;
1479 }
1480
1481 /*
1482 * The last two values are not from the RFC but
1483 * are needed for AMPRnet AX.25 paths.
1484 */
1485
1486 static const unsigned short mtu_plateau[] =
1487 {32000, 17914, 8166, 4352, 2002, 1492, 576, 296, 216, 128 };
1488
1489 static inline unsigned short guess_mtu(unsigned short old_mtu)
1490 {
1491 int i;
1492
1493 for (i = 0; i < ARRAY_SIZE(mtu_plateau); i++)
1494 if (old_mtu > mtu_plateau[i])
1495 return mtu_plateau[i];
1496 return 68;
1497 }
1498
1499 unsigned short ip_rt_frag_needed(struct net *net, const struct iphdr *iph,
1500 unsigned short new_mtu,
1501 struct net_device *dev)
1502 {
1503 unsigned short old_mtu = ntohs(iph->tot_len);
1504 unsigned short est_mtu = 0;
1505 struct inet_peer *peer;
1506
1507 peer = inet_getpeer_v4(iph->daddr, 1);
1508 if (peer) {
1509 unsigned short mtu = new_mtu;
1510
1511 if (new_mtu < 68 || new_mtu >= old_mtu) {
1512 /* BSD 4.2 derived systems incorrectly adjust
1513 * tot_len by the IP header length, and report
1514 * a zero MTU in the ICMP message.
1515 */
1516 if (mtu == 0 &&
1517 old_mtu >= 68 + (iph->ihl << 2))
1518 old_mtu -= iph->ihl << 2;
1519 mtu = guess_mtu(old_mtu);
1520 }
1521
1522 if (mtu < ip_rt_min_pmtu)
1523 mtu = ip_rt_min_pmtu;
1524 if (!peer->pmtu_expires || mtu < peer->pmtu_learned) {
1525 unsigned long pmtu_expires;
1526
1527 pmtu_expires = jiffies + ip_rt_mtu_expires;
1528 if (!pmtu_expires)
1529 pmtu_expires = 1UL;
1530
1531 est_mtu = mtu;
1532 peer->pmtu_learned = mtu;
1533 peer->pmtu_expires = pmtu_expires;
1534 }
1535
1536 inet_putpeer(peer);
1537
1538 atomic_inc(&__rt_peer_genid);
1539 }
1540 return est_mtu ? : new_mtu;
1541 }
1542
1543 static void check_peer_pmtu(struct dst_entry *dst, struct inet_peer *peer)
1544 {
1545 unsigned long expires = ACCESS_ONCE(peer->pmtu_expires);
1546
1547 if (!expires)
1548 return;
1549 if (time_before(jiffies, expires)) {
1550 u32 orig_dst_mtu = dst_mtu(dst);
1551 if (peer->pmtu_learned < orig_dst_mtu) {
1552 if (!peer->pmtu_orig)
1553 peer->pmtu_orig = dst_metric_raw(dst, RTAX_MTU);
1554 dst_metric_set(dst, RTAX_MTU, peer->pmtu_learned);
1555 }
1556 } else if (cmpxchg(&peer->pmtu_expires, expires, 0) == expires)
1557 dst_metric_set(dst, RTAX_MTU, peer->pmtu_orig);
1558 }
1559
1560 static void ip_rt_update_pmtu(struct dst_entry *dst, u32 mtu)
1561 {
1562 struct rtable *rt = (struct rtable *) dst;
1563 struct inet_peer *peer;
1564
1565 dst_confirm(dst);
1566
1567 if (!rt->peer)
1568 rt_bind_peer(rt, rt->rt_dst, 1);
1569 peer = rt->peer;
1570 if (peer) {
1571 unsigned long pmtu_expires = ACCESS_ONCE(peer->pmtu_expires);
1572
1573 if (mtu < ip_rt_min_pmtu)
1574 mtu = ip_rt_min_pmtu;
1575 if (!pmtu_expires || mtu < peer->pmtu_learned) {
1576
1577 pmtu_expires = jiffies + ip_rt_mtu_expires;
1578 if (!pmtu_expires)
1579 pmtu_expires = 1UL;
1580
1581 peer->pmtu_learned = mtu;
1582 peer->pmtu_expires = pmtu_expires;
1583
1584 atomic_inc(&__rt_peer_genid);
1585 rt->rt_peer_genid = rt_peer_genid();
1586 }
1587 check_peer_pmtu(dst, peer);
1588 }
1589 }
1590
1591 static int check_peer_redir(struct dst_entry *dst, struct inet_peer *peer)
1592 {
1593 struct rtable *rt = (struct rtable *) dst;
1594 __be32 orig_gw = rt->rt_gateway;
1595
1596 dst_confirm(&rt->dst);
1597
1598 neigh_release(rt->dst.neighbour);
1599 rt->dst.neighbour = NULL;
1600
1601 rt->rt_gateway = peer->redirect_learned.a4;
1602 if (arp_bind_neighbour(&rt->dst) ||
1603 !(rt->dst.neighbour->nud_state & NUD_VALID)) {
1604 if (rt->dst.neighbour)
1605 neigh_event_send(rt->dst.neighbour, NULL);
1606 rt->rt_gateway = orig_gw;
1607 return -EAGAIN;
1608 } else {
1609 rt->rt_flags |= RTCF_REDIRECTED;
1610 call_netevent_notifiers(NETEVENT_NEIGH_UPDATE,
1611 rt->dst.neighbour);
1612 }
1613 return 0;
1614 }
1615
1616 static struct dst_entry *ipv4_dst_check(struct dst_entry *dst, u32 cookie)
1617 {
1618 struct rtable *rt = (struct rtable *) dst;
1619
1620 if (rt_is_expired(rt))
1621 return NULL;
1622 if (rt->rt_peer_genid != rt_peer_genid()) {
1623 struct inet_peer *peer;
1624
1625 if (!rt->peer)
1626 rt_bind_peer(rt, rt->rt_dst, 0);
1627
1628 peer = rt->peer;
1629 if (peer) {
1630 check_peer_pmtu(dst, peer);
1631
1632 if (peer->redirect_learned.a4 &&
1633 peer->redirect_learned.a4 != rt->rt_gateway) {
1634 if (check_peer_redir(dst, peer))
1635 return NULL;
1636 }
1637 }
1638
1639 rt->rt_peer_genid = rt_peer_genid();
1640 }
1641 return dst;
1642 }
1643
1644 static void ipv4_dst_destroy(struct dst_entry *dst)
1645 {
1646 struct rtable *rt = (struct rtable *) dst;
1647 struct inet_peer *peer = rt->peer;
1648
1649 if (rt->fi) {
1650 fib_info_put(rt->fi);
1651 rt->fi = NULL;
1652 }
1653 if (peer) {
1654 rt->peer = NULL;
1655 inet_putpeer(peer);
1656 }
1657 }
1658
1659
1660 static void ipv4_link_failure(struct sk_buff *skb)
1661 {
1662 struct rtable *rt;
1663
1664 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_HOST_UNREACH, 0);
1665
1666 rt = skb_rtable(skb);
1667 if (rt && rt->peer && peer_pmtu_cleaned(rt->peer))
1668 dst_metric_set(&rt->dst, RTAX_MTU, rt->peer->pmtu_orig);
1669 }
1670
1671 static int ip_rt_bug(struct sk_buff *skb)
1672 {
1673 printk(KERN_DEBUG "ip_rt_bug: %pI4 -> %pI4, %s\n",
1674 &ip_hdr(skb)->saddr, &ip_hdr(skb)->daddr,
1675 skb->dev ? skb->dev->name : "?");
1676 kfree_skb(skb);
1677 WARN_ON(1);
1678 return 0;
1679 }
1680
1681 /*
1682 We do not cache source address of outgoing interface,
1683 because it is used only by IP RR, TS and SRR options,
1684 so that it out of fast path.
1685
1686 BTW remember: "addr" is allowed to be not aligned
1687 in IP options!
1688 */
1689
1690 void ip_rt_get_source(u8 *addr, struct sk_buff *skb, struct rtable *rt)
1691 {
1692 __be32 src;
1693
1694 if (rt_is_output_route(rt))
1695 src = ip_hdr(skb)->saddr;
1696 else {
1697 struct fib_result res;
1698 struct flowi4 fl4;
1699 struct iphdr *iph;
1700
1701 iph = ip_hdr(skb);
1702
1703 memset(&fl4, 0, sizeof(fl4));
1704 fl4.daddr = iph->daddr;
1705 fl4.saddr = iph->saddr;
1706 fl4.flowi4_tos = iph->tos;
1707 fl4.flowi4_oif = rt->dst.dev->ifindex;
1708 fl4.flowi4_iif = skb->dev->ifindex;
1709 fl4.flowi4_mark = skb->mark;
1710
1711 rcu_read_lock();
1712 if (fib_lookup(dev_net(rt->dst.dev), &fl4, &res) == 0)
1713 src = FIB_RES_PREFSRC(dev_net(rt->dst.dev), res);
1714 else
1715 src = inet_select_addr(rt->dst.dev, rt->rt_gateway,
1716 RT_SCOPE_UNIVERSE);
1717 rcu_read_unlock();
1718 }
1719 memcpy(addr, &src, 4);
1720 }
1721
1722 #ifdef CONFIG_IP_ROUTE_CLASSID
1723 static void set_class_tag(struct rtable *rt, u32 tag)
1724 {
1725 if (!(rt->dst.tclassid & 0xFFFF))
1726 rt->dst.tclassid |= tag & 0xFFFF;
1727 if (!(rt->dst.tclassid & 0xFFFF0000))
1728 rt->dst.tclassid |= tag & 0xFFFF0000;
1729 }
1730 #endif
1731
1732 static unsigned int ipv4_default_advmss(const struct dst_entry *dst)
1733 {
1734 unsigned int advmss = dst_metric_raw(dst, RTAX_ADVMSS);
1735
1736 if (advmss == 0) {
1737 advmss = max_t(unsigned int, dst->dev->mtu - 40,
1738 ip_rt_min_advmss);
1739 if (advmss > 65535 - 40)
1740 advmss = 65535 - 40;
1741 }
1742 return advmss;
1743 }
1744
1745 static unsigned int ipv4_default_mtu(const struct dst_entry *dst)
1746 {
1747 unsigned int mtu = dst->dev->mtu;
1748
1749 if (unlikely(dst_metric_locked(dst, RTAX_MTU))) {
1750 const struct rtable *rt = (const struct rtable *) dst;
1751
1752 if (rt->rt_gateway != rt->rt_dst && mtu > 576)
1753 mtu = 576;
1754 }
1755
1756 if (mtu > IP_MAX_MTU)
1757 mtu = IP_MAX_MTU;
1758
1759 return mtu;
1760 }
1761
1762 static void rt_init_metrics(struct rtable *rt, const struct flowi4 *fl4,
1763 struct fib_info *fi)
1764 {
1765 struct inet_peer *peer;
1766 int create = 0;
1767
1768 /* If a peer entry exists for this destination, we must hook
1769 * it up in order to get at cached metrics.
1770 */
1771 if (fl4 && (fl4->flowi4_flags & FLOWI_FLAG_PRECOW_METRICS))
1772 create = 1;
1773
1774 rt->peer = peer = inet_getpeer_v4(rt->rt_dst, create);
1775 if (peer) {
1776 rt->rt_peer_genid = rt_peer_genid();
1777 if (inet_metrics_new(peer))
1778 memcpy(peer->metrics, fi->fib_metrics,
1779 sizeof(u32) * RTAX_MAX);
1780 dst_init_metrics(&rt->dst, peer->metrics, false);
1781
1782 check_peer_pmtu(&rt->dst, peer);
1783 if (peer->redirect_learned.a4 &&
1784 peer->redirect_learned.a4 != rt->rt_gateway) {
1785 rt->rt_gateway = peer->redirect_learned.a4;
1786 rt->rt_flags |= RTCF_REDIRECTED;
1787 }
1788 } else {
1789 if (fi->fib_metrics != (u32 *) dst_default_metrics) {
1790 rt->fi = fi;
1791 atomic_inc(&fi->fib_clntref);
1792 }
1793 dst_init_metrics(&rt->dst, fi->fib_metrics, true);
1794 }
1795 }
1796
1797 static void rt_set_nexthop(struct rtable *rt, const struct flowi4 *fl4,
1798 const struct fib_result *res,
1799 struct fib_info *fi, u16 type, u32 itag)
1800 {
1801 struct dst_entry *dst = &rt->dst;
1802
1803 if (fi) {
1804 if (FIB_RES_GW(*res) &&
1805 FIB_RES_NH(*res).nh_scope == RT_SCOPE_LINK)
1806 rt->rt_gateway = FIB_RES_GW(*res);
1807 rt_init_metrics(rt, fl4, fi);
1808 #ifdef CONFIG_IP_ROUTE_CLASSID
1809 dst->tclassid = FIB_RES_NH(*res).nh_tclassid;
1810 #endif
1811 }
1812
1813 if (dst_mtu(dst) > IP_MAX_MTU)
1814 dst_metric_set(dst, RTAX_MTU, IP_MAX_MTU);
1815 if (dst_metric_raw(dst, RTAX_ADVMSS) > 65535 - 40)
1816 dst_metric_set(dst, RTAX_ADVMSS, 65535 - 40);
1817
1818 #ifdef CONFIG_IP_ROUTE_CLASSID
1819 #ifdef CONFIG_IP_MULTIPLE_TABLES
1820 set_class_tag(rt, fib_rules_tclass(res));
1821 #endif
1822 set_class_tag(rt, itag);
1823 #endif
1824 }
1825
1826 static struct rtable *rt_dst_alloc(struct net_device *dev,
1827 bool nopolicy, bool noxfrm)
1828 {
1829 return dst_alloc(&ipv4_dst_ops, dev, 1, -1,
1830 DST_HOST |
1831 (nopolicy ? DST_NOPOLICY : 0) |
1832 (noxfrm ? DST_NOXFRM : 0));
1833 }
1834
1835 /* called in rcu_read_lock() section */
1836 static int ip_route_input_mc(struct sk_buff *skb, __be32 daddr, __be32 saddr,
1837 u8 tos, struct net_device *dev, int our)
1838 {
1839 unsigned int hash;
1840 struct rtable *rth;
1841 __be32 spec_dst;
1842 struct in_device *in_dev = __in_dev_get_rcu(dev);
1843 u32 itag = 0;
1844 int err;
1845
1846 /* Primary sanity checks. */
1847
1848 if (in_dev == NULL)
1849 return -EINVAL;
1850
1851 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr) ||
1852 ipv4_is_loopback(saddr) || skb->protocol != htons(ETH_P_IP))
1853 goto e_inval;
1854
1855 if (ipv4_is_zeronet(saddr)) {
1856 if (!ipv4_is_local_multicast(daddr))
1857 goto e_inval;
1858 spec_dst = inet_select_addr(dev, 0, RT_SCOPE_LINK);
1859 } else {
1860 err = fib_validate_source(skb, saddr, 0, tos, 0, dev, &spec_dst,
1861 &itag);
1862 if (err < 0)
1863 goto e_err;
1864 }
1865 rth = rt_dst_alloc(init_net.loopback_dev,
1866 IN_DEV_CONF_GET(in_dev, NOPOLICY), false);
1867 if (!rth)
1868 goto e_nobufs;
1869
1870 #ifdef CONFIG_IP_ROUTE_CLASSID
1871 rth->dst.tclassid = itag;
1872 #endif
1873 rth->dst.output = ip_rt_bug;
1874
1875 rth->rt_key_dst = daddr;
1876 rth->rt_key_src = saddr;
1877 rth->rt_genid = rt_genid(dev_net(dev));
1878 rth->rt_flags = RTCF_MULTICAST;
1879 rth->rt_type = RTN_MULTICAST;
1880 rth->rt_key_tos = tos;
1881 rth->rt_dst = daddr;
1882 rth->rt_src = saddr;
1883 rth->rt_route_iif = dev->ifindex;
1884 rth->rt_iif = dev->ifindex;
1885 rth->rt_oif = 0;
1886 rth->rt_mark = skb->mark;
1887 rth->rt_gateway = daddr;
1888 rth->rt_spec_dst= spec_dst;
1889 rth->rt_peer_genid = 0;
1890 rth->peer = NULL;
1891 rth->fi = NULL;
1892 if (our) {
1893 rth->dst.input= ip_local_deliver;
1894 rth->rt_flags |= RTCF_LOCAL;
1895 }
1896
1897 #ifdef CONFIG_IP_MROUTE
1898 if (!ipv4_is_local_multicast(daddr) && IN_DEV_MFORWARD(in_dev))
1899 rth->dst.input = ip_mr_input;
1900 #endif
1901 RT_CACHE_STAT_INC(in_slow_mc);
1902
1903 hash = rt_hash(daddr, saddr, dev->ifindex, rt_genid(dev_net(dev)));
1904 rth = rt_intern_hash(hash, rth, skb, dev->ifindex);
1905 err = 0;
1906 if (IS_ERR(rth))
1907 err = PTR_ERR(rth);
1908
1909 e_nobufs:
1910 return -ENOBUFS;
1911 e_inval:
1912 return -EINVAL;
1913 e_err:
1914 return err;
1915 }
1916
1917
1918 static void ip_handle_martian_source(struct net_device *dev,
1919 struct in_device *in_dev,
1920 struct sk_buff *skb,
1921 __be32 daddr,
1922 __be32 saddr)
1923 {
1924 RT_CACHE_STAT_INC(in_martian_src);
1925 #ifdef CONFIG_IP_ROUTE_VERBOSE
1926 if (IN_DEV_LOG_MARTIANS(in_dev) && net_ratelimit()) {
1927 /*
1928 * RFC1812 recommendation, if source is martian,
1929 * the only hint is MAC header.
1930 */
1931 printk(KERN_WARNING "martian source %pI4 from %pI4, on dev %s\n",
1932 &daddr, &saddr, dev->name);
1933 if (dev->hard_header_len && skb_mac_header_was_set(skb)) {
1934 int i;
1935 const unsigned char *p = skb_mac_header(skb);
1936 printk(KERN_WARNING "ll header: ");
1937 for (i = 0; i < dev->hard_header_len; i++, p++) {
1938 printk("%02x", *p);
1939 if (i < (dev->hard_header_len - 1))
1940 printk(":");
1941 }
1942 printk("\n");
1943 }
1944 }
1945 #endif
1946 }
1947
1948 /* called in rcu_read_lock() section */
1949 static int __mkroute_input(struct sk_buff *skb,
1950 const struct fib_result *res,
1951 struct in_device *in_dev,
1952 __be32 daddr, __be32 saddr, u32 tos,
1953 struct rtable **result)
1954 {
1955 struct rtable *rth;
1956 int err;
1957 struct in_device *out_dev;
1958 unsigned int flags = 0;
1959 __be32 spec_dst;
1960 u32 itag;
1961
1962 /* get a working reference to the output device */
1963 out_dev = __in_dev_get_rcu(FIB_RES_DEV(*res));
1964 if (out_dev == NULL) {
1965 if (net_ratelimit())
1966 printk(KERN_CRIT "Bug in ip_route_input" \
1967 "_slow(). Please, report\n");
1968 return -EINVAL;
1969 }
1970
1971
1972 err = fib_validate_source(skb, saddr, daddr, tos, FIB_RES_OIF(*res),
1973 in_dev->dev, &spec_dst, &itag);
1974 if (err < 0) {
1975 ip_handle_martian_source(in_dev->dev, in_dev, skb, daddr,
1976 saddr);
1977
1978 goto cleanup;
1979 }
1980
1981 if (err)
1982 flags |= RTCF_DIRECTSRC;
1983
1984 if (out_dev == in_dev && err &&
1985 (IN_DEV_SHARED_MEDIA(out_dev) ||
1986 inet_addr_onlink(out_dev, saddr, FIB_RES_GW(*res))))
1987 flags |= RTCF_DOREDIRECT;
1988
1989 if (skb->protocol != htons(ETH_P_IP)) {
1990 /* Not IP (i.e. ARP). Do not create route, if it is
1991 * invalid for proxy arp. DNAT routes are always valid.
1992 *
1993 * Proxy arp feature have been extended to allow, ARP
1994 * replies back to the same interface, to support
1995 * Private VLAN switch technologies. See arp.c.
1996 */
1997 if (out_dev == in_dev &&
1998 IN_DEV_PROXY_ARP_PVLAN(in_dev) == 0) {
1999 err = -EINVAL;
2000 goto cleanup;
2001 }
2002 }
2003
2004 rth = rt_dst_alloc(out_dev->dev,
2005 IN_DEV_CONF_GET(in_dev, NOPOLICY),
2006 IN_DEV_CONF_GET(out_dev, NOXFRM));
2007 if (!rth) {
2008 err = -ENOBUFS;
2009 goto cleanup;
2010 }
2011
2012 rth->rt_key_dst = daddr;
2013 rth->rt_key_src = saddr;
2014 rth->rt_genid = rt_genid(dev_net(rth->dst.dev));
2015 rth->rt_flags = flags;
2016 rth->rt_type = res->type;
2017 rth->rt_key_tos = tos;
2018 rth->rt_dst = daddr;
2019 rth->rt_src = saddr;
2020 rth->rt_route_iif = in_dev->dev->ifindex;
2021 rth->rt_iif = in_dev->dev->ifindex;
2022 rth->rt_oif = 0;
2023 rth->rt_mark = skb->mark;
2024 rth->rt_gateway = daddr;
2025 rth->rt_spec_dst= spec_dst;
2026 rth->rt_peer_genid = 0;
2027 rth->peer = NULL;
2028 rth->fi = NULL;
2029
2030 rth->dst.input = ip_forward;
2031 rth->dst.output = ip_output;
2032
2033 rt_set_nexthop(rth, NULL, res, res->fi, res->type, itag);
2034
2035 *result = rth;
2036 err = 0;
2037 cleanup:
2038 return err;
2039 }
2040
2041 static int ip_mkroute_input(struct sk_buff *skb,
2042 struct fib_result *res,
2043 const struct flowi4 *fl4,
2044 struct in_device *in_dev,
2045 __be32 daddr, __be32 saddr, u32 tos)
2046 {
2047 struct rtable* rth = NULL;
2048 int err;
2049 unsigned hash;
2050
2051 #ifdef CONFIG_IP_ROUTE_MULTIPATH
2052 if (res->fi && res->fi->fib_nhs > 1)
2053 fib_select_multipath(res);
2054 #endif
2055
2056 /* create a routing cache entry */
2057 err = __mkroute_input(skb, res, in_dev, daddr, saddr, tos, &rth);
2058 if (err)
2059 return err;
2060
2061 /* put it into the cache */
2062 hash = rt_hash(daddr, saddr, fl4->flowi4_iif,
2063 rt_genid(dev_net(rth->dst.dev)));
2064 rth = rt_intern_hash(hash, rth, skb, fl4->flowi4_iif);
2065 if (IS_ERR(rth))
2066 return PTR_ERR(rth);
2067 return 0;
2068 }
2069
2070 /*
2071 * NOTE. We drop all the packets that has local source
2072 * addresses, because every properly looped back packet
2073 * must have correct destination already attached by output routine.
2074 *
2075 * Such approach solves two big problems:
2076 * 1. Not simplex devices are handled properly.
2077 * 2. IP spoofing attempts are filtered with 100% of guarantee.
2078 * called with rcu_read_lock()
2079 */
2080
2081 static int ip_route_input_slow(struct sk_buff *skb, __be32 daddr, __be32 saddr,
2082 u8 tos, struct net_device *dev)
2083 {
2084 struct fib_result res;
2085 struct in_device *in_dev = __in_dev_get_rcu(dev);
2086 struct flowi4 fl4;
2087 unsigned flags = 0;
2088 u32 itag = 0;
2089 struct rtable * rth;
2090 unsigned hash;
2091 __be32 spec_dst;
2092 int err = -EINVAL;
2093 struct net * net = dev_net(dev);
2094
2095 /* IP on this device is disabled. */
2096
2097 if (!in_dev)
2098 goto out;
2099
2100 /* Check for the most weird martians, which can be not detected
2101 by fib_lookup.
2102 */
2103
2104 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr) ||
2105 ipv4_is_loopback(saddr))
2106 goto martian_source;
2107
2108 if (ipv4_is_lbcast(daddr) || (saddr == 0 && daddr == 0))
2109 goto brd_input;
2110
2111 /* Accept zero addresses only to limited broadcast;
2112 * I even do not know to fix it or not. Waiting for complains :-)
2113 */
2114 if (ipv4_is_zeronet(saddr))
2115 goto martian_source;
2116
2117 if (ipv4_is_zeronet(daddr) || ipv4_is_loopback(daddr))
2118 goto martian_destination;
2119
2120 /*
2121 * Now we are ready to route packet.
2122 */
2123 fl4.flowi4_oif = 0;
2124 fl4.flowi4_iif = dev->ifindex;
2125 fl4.flowi4_mark = skb->mark;
2126 fl4.flowi4_tos = tos;
2127 fl4.flowi4_scope = RT_SCOPE_UNIVERSE;
2128 fl4.daddr = daddr;
2129 fl4.saddr = saddr;
2130 err = fib_lookup(net, &fl4, &res);
2131 if (err != 0) {
2132 if (!IN_DEV_FORWARD(in_dev))
2133 goto e_hostunreach;
2134 goto no_route;
2135 }
2136
2137 RT_CACHE_STAT_INC(in_slow_tot);
2138
2139 if (res.type == RTN_BROADCAST)
2140 goto brd_input;
2141
2142 if (res.type == RTN_LOCAL) {
2143 err = fib_validate_source(skb, saddr, daddr, tos,
2144 net->loopback_dev->ifindex,
2145 dev, &spec_dst, &itag);
2146 if (err < 0)
2147 goto martian_source_keep_err;
2148 if (err)
2149 flags |= RTCF_DIRECTSRC;
2150 spec_dst = daddr;
2151 goto local_input;
2152 }
2153
2154 if (!IN_DEV_FORWARD(in_dev))
2155 goto e_hostunreach;
2156 if (res.type != RTN_UNICAST)
2157 goto martian_destination;
2158
2159 err = ip_mkroute_input(skb, &res, &fl4, in_dev, daddr, saddr, tos);
2160 out: return err;
2161
2162 brd_input:
2163 if (skb->protocol != htons(ETH_P_IP))
2164 goto e_inval;
2165
2166 if (ipv4_is_zeronet(saddr))
2167 spec_dst = inet_select_addr(dev, 0, RT_SCOPE_LINK);
2168 else {
2169 err = fib_validate_source(skb, saddr, 0, tos, 0, dev, &spec_dst,
2170 &itag);
2171 if (err < 0)
2172 goto martian_source_keep_err;
2173 if (err)
2174 flags |= RTCF_DIRECTSRC;
2175 }
2176 flags |= RTCF_BROADCAST;
2177 res.type = RTN_BROADCAST;
2178 RT_CACHE_STAT_INC(in_brd);
2179
2180 local_input:
2181 rth = rt_dst_alloc(net->loopback_dev,
2182 IN_DEV_CONF_GET(in_dev, NOPOLICY), false);
2183 if (!rth)
2184 goto e_nobufs;
2185
2186 rth->dst.input= ip_local_deliver;
2187 rth->dst.output= ip_rt_bug;
2188 #ifdef CONFIG_IP_ROUTE_CLASSID
2189 rth->dst.tclassid = itag;
2190 #endif
2191
2192 rth->rt_key_dst = daddr;
2193 rth->rt_key_src = saddr;
2194 rth->rt_genid = rt_genid(net);
2195 rth->rt_flags = flags|RTCF_LOCAL;
2196 rth->rt_type = res.type;
2197 rth->rt_key_tos = tos;
2198 rth->rt_dst = daddr;
2199 rth->rt_src = saddr;
2200 #ifdef CONFIG_IP_ROUTE_CLASSID
2201 rth->dst.tclassid = itag;
2202 #endif
2203 rth->rt_route_iif = dev->ifindex;
2204 rth->rt_iif = dev->ifindex;
2205 rth->rt_oif = 0;
2206 rth->rt_mark = skb->mark;
2207 rth->rt_gateway = daddr;
2208 rth->rt_spec_dst= spec_dst;
2209 rth->rt_peer_genid = 0;
2210 rth->peer = NULL;
2211 rth->fi = NULL;
2212 if (res.type == RTN_UNREACHABLE) {
2213 rth->dst.input= ip_error;
2214 rth->dst.error= -err;
2215 rth->rt_flags &= ~RTCF_LOCAL;
2216 }
2217 hash = rt_hash(daddr, saddr, fl4.flowi4_iif, rt_genid(net));
2218 rth = rt_intern_hash(hash, rth, skb, fl4.flowi4_iif);
2219 err = 0;
2220 if (IS_ERR(rth))
2221 err = PTR_ERR(rth);
2222 goto out;
2223
2224 no_route:
2225 RT_CACHE_STAT_INC(in_no_route);
2226 spec_dst = inet_select_addr(dev, 0, RT_SCOPE_UNIVERSE);
2227 res.type = RTN_UNREACHABLE;
2228 if (err == -ESRCH)
2229 err = -ENETUNREACH;
2230 goto local_input;
2231
2232 /*
2233 * Do not cache martian addresses: they should be logged (RFC1812)
2234 */
2235 martian_destination:
2236 RT_CACHE_STAT_INC(in_martian_dst);
2237 #ifdef CONFIG_IP_ROUTE_VERBOSE
2238 if (IN_DEV_LOG_MARTIANS(in_dev) && net_ratelimit())
2239 printk(KERN_WARNING "martian destination %pI4 from %pI4, dev %s\n",
2240 &daddr, &saddr, dev->name);
2241 #endif
2242
2243 e_hostunreach:
2244 err = -EHOSTUNREACH;
2245 goto out;
2246
2247 e_inval:
2248 err = -EINVAL;
2249 goto out;
2250
2251 e_nobufs:
2252 err = -ENOBUFS;
2253 goto out;
2254
2255 martian_source:
2256 err = -EINVAL;
2257 martian_source_keep_err:
2258 ip_handle_martian_source(dev, in_dev, skb, daddr, saddr);
2259 goto out;
2260 }
2261
2262 int ip_route_input_common(struct sk_buff *skb, __be32 daddr, __be32 saddr,
2263 u8 tos, struct net_device *dev, bool noref)
2264 {
2265 struct rtable * rth;
2266 unsigned hash;
2267 int iif = dev->ifindex;
2268 struct net *net;
2269 int res;
2270
2271 net = dev_net(dev);
2272
2273 rcu_read_lock();
2274
2275 if (!rt_caching(net))
2276 goto skip_cache;
2277
2278 tos &= IPTOS_RT_MASK;
2279 hash = rt_hash(daddr, saddr, iif, rt_genid(net));
2280
2281 for (rth = rcu_dereference(rt_hash_table[hash].chain); rth;
2282 rth = rcu_dereference(rth->dst.rt_next)) {
2283 if ((((__force u32)rth->rt_key_dst ^ (__force u32)daddr) |
2284 ((__force u32)rth->rt_key_src ^ (__force u32)saddr) |
2285 (rth->rt_iif ^ iif) |
2286 rth->rt_oif |
2287 (rth->rt_key_tos ^ tos)) == 0 &&
2288 rth->rt_mark == skb->mark &&
2289 net_eq(dev_net(rth->dst.dev), net) &&
2290 !rt_is_expired(rth)) {
2291 if (noref) {
2292 dst_use_noref(&rth->dst, jiffies);
2293 skb_dst_set_noref(skb, &rth->dst);
2294 } else {
2295 dst_use(&rth->dst, jiffies);
2296 skb_dst_set(skb, &rth->dst);
2297 }
2298 RT_CACHE_STAT_INC(in_hit);
2299 rcu_read_unlock();
2300 return 0;
2301 }
2302 RT_CACHE_STAT_INC(in_hlist_search);
2303 }
2304
2305 skip_cache:
2306 /* Multicast recognition logic is moved from route cache to here.
2307 The problem was that too many Ethernet cards have broken/missing
2308 hardware multicast filters :-( As result the host on multicasting
2309 network acquires a lot of useless route cache entries, sort of
2310 SDR messages from all the world. Now we try to get rid of them.
2311 Really, provided software IP multicast filter is organized
2312 reasonably (at least, hashed), it does not result in a slowdown
2313 comparing with route cache reject entries.
2314 Note, that multicast routers are not affected, because
2315 route cache entry is created eventually.
2316 */
2317 if (ipv4_is_multicast(daddr)) {
2318 struct in_device *in_dev = __in_dev_get_rcu(dev);
2319
2320 if (in_dev) {
2321 int our = ip_check_mc_rcu(in_dev, daddr, saddr,
2322 ip_hdr(skb)->protocol);
2323 if (our
2324 #ifdef CONFIG_IP_MROUTE
2325 ||
2326 (!ipv4_is_local_multicast(daddr) &&
2327 IN_DEV_MFORWARD(in_dev))
2328 #endif
2329 ) {
2330 int res = ip_route_input_mc(skb, daddr, saddr,
2331 tos, dev, our);
2332 rcu_read_unlock();
2333 return res;
2334 }
2335 }
2336 rcu_read_unlock();
2337 return -EINVAL;
2338 }
2339 res = ip_route_input_slow(skb, daddr, saddr, tos, dev);
2340 rcu_read_unlock();
2341 return res;
2342 }
2343 EXPORT_SYMBOL(ip_route_input_common);
2344
2345 /* called with rcu_read_lock() */
2346 static struct rtable *__mkroute_output(const struct fib_result *res,
2347 const struct flowi4 *fl4,
2348 __be32 orig_daddr, __be32 orig_saddr,
2349 int orig_oif, struct net_device *dev_out,
2350 unsigned int flags)
2351 {
2352 struct fib_info *fi = res->fi;
2353 u32 tos = RT_FL_TOS(fl4);
2354 struct in_device *in_dev;
2355 u16 type = res->type;
2356 struct rtable *rth;
2357
2358 if (ipv4_is_loopback(fl4->saddr) && !(dev_out->flags & IFF_LOOPBACK))
2359 return ERR_PTR(-EINVAL);
2360
2361 if (ipv4_is_lbcast(fl4->daddr))
2362 type = RTN_BROADCAST;
2363 else if (ipv4_is_multicast(fl4->daddr))
2364 type = RTN_MULTICAST;
2365 else if (ipv4_is_zeronet(fl4->daddr))
2366 return ERR_PTR(-EINVAL);
2367
2368 if (dev_out->flags & IFF_LOOPBACK)
2369 flags |= RTCF_LOCAL;
2370
2371 in_dev = __in_dev_get_rcu(dev_out);
2372 if (!in_dev)
2373 return ERR_PTR(-EINVAL);
2374
2375 if (type == RTN_BROADCAST) {
2376 flags |= RTCF_BROADCAST | RTCF_LOCAL;
2377 fi = NULL;
2378 } else if (type == RTN_MULTICAST) {
2379 flags |= RTCF_MULTICAST | RTCF_LOCAL;
2380 if (!ip_check_mc_rcu(in_dev, fl4->daddr, fl4->saddr,
2381 fl4->flowi4_proto))
2382 flags &= ~RTCF_LOCAL;
2383 /* If multicast route do not exist use
2384 * default one, but do not gateway in this case.
2385 * Yes, it is hack.
2386 */
2387 if (fi && res->prefixlen < 4)
2388 fi = NULL;
2389 }
2390
2391 rth = rt_dst_alloc(dev_out,
2392 IN_DEV_CONF_GET(in_dev, NOPOLICY),
2393 IN_DEV_CONF_GET(in_dev, NOXFRM));
2394 if (!rth)
2395 return ERR_PTR(-ENOBUFS);
2396
2397 rth->dst.output = ip_output;
2398
2399 rth->rt_key_dst = orig_daddr;
2400 rth->rt_key_src = orig_saddr;
2401 rth->rt_genid = rt_genid(dev_net(dev_out));
2402 rth->rt_flags = flags;
2403 rth->rt_type = type;
2404 rth->rt_key_tos = tos;
2405 rth->rt_dst = fl4->daddr;
2406 rth->rt_src = fl4->saddr;
2407 rth->rt_route_iif = 0;
2408 rth->rt_iif = orig_oif ? : dev_out->ifindex;
2409 rth->rt_oif = orig_oif;
2410 rth->rt_mark = fl4->flowi4_mark;
2411 rth->rt_gateway = fl4->daddr;
2412 rth->rt_spec_dst= fl4->saddr;
2413 rth->rt_peer_genid = 0;
2414 rth->peer = NULL;
2415 rth->fi = NULL;
2416
2417 RT_CACHE_STAT_INC(out_slow_tot);
2418
2419 if (flags & RTCF_LOCAL) {
2420 rth->dst.input = ip_local_deliver;
2421 rth->rt_spec_dst = fl4->daddr;
2422 }
2423 if (flags & (RTCF_BROADCAST | RTCF_MULTICAST)) {
2424 rth->rt_spec_dst = fl4->saddr;
2425 if (flags & RTCF_LOCAL &&
2426 !(dev_out->flags & IFF_LOOPBACK)) {
2427 rth->dst.output = ip_mc_output;
2428 RT_CACHE_STAT_INC(out_slow_mc);
2429 }
2430 #ifdef CONFIG_IP_MROUTE
2431 if (type == RTN_MULTICAST) {
2432 if (IN_DEV_MFORWARD(in_dev) &&
2433 !ipv4_is_local_multicast(fl4->daddr)) {
2434 rth->dst.input = ip_mr_input;
2435 rth->dst.output = ip_mc_output;
2436 }
2437 }
2438 #endif
2439 }
2440
2441 rt_set_nexthop(rth, fl4, res, fi, type, 0);
2442
2443 return rth;
2444 }
2445
2446 /*
2447 * Major route resolver routine.
2448 * called with rcu_read_lock();
2449 */
2450
2451 static struct rtable *ip_route_output_slow(struct net *net, struct flowi4 *fl4)
2452 {
2453 struct net_device *dev_out = NULL;
2454 u32 tos = RT_FL_TOS(fl4);
2455 unsigned int flags = 0;
2456 struct fib_result res;
2457 struct rtable *rth;
2458 __be32 orig_daddr;
2459 __be32 orig_saddr;
2460 int orig_oif;
2461
2462 res.fi = NULL;
2463 #ifdef CONFIG_IP_MULTIPLE_TABLES
2464 res.r = NULL;
2465 #endif
2466
2467 orig_daddr = fl4->daddr;
2468 orig_saddr = fl4->saddr;
2469 orig_oif = fl4->flowi4_oif;
2470
2471 fl4->flowi4_iif = net->loopback_dev->ifindex;
2472 fl4->flowi4_tos = tos & IPTOS_RT_MASK;
2473 fl4->flowi4_scope = ((tos & RTO_ONLINK) ?
2474 RT_SCOPE_LINK : RT_SCOPE_UNIVERSE);
2475
2476 rcu_read_lock();
2477 if (fl4->saddr) {
2478 rth = ERR_PTR(-EINVAL);
2479 if (ipv4_is_multicast(fl4->saddr) ||
2480 ipv4_is_lbcast(fl4->saddr) ||
2481 ipv4_is_zeronet(fl4->saddr))
2482 goto out;
2483
2484 /* I removed check for oif == dev_out->oif here.
2485 It was wrong for two reasons:
2486 1. ip_dev_find(net, saddr) can return wrong iface, if saddr
2487 is assigned to multiple interfaces.
2488 2. Moreover, we are allowed to send packets with saddr
2489 of another iface. --ANK
2490 */
2491
2492 if (fl4->flowi4_oif == 0 &&
2493 (ipv4_is_multicast(fl4->daddr) ||
2494 ipv4_is_lbcast(fl4->daddr))) {
2495 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */
2496 dev_out = __ip_dev_find(net, fl4->saddr, false);
2497 if (dev_out == NULL)
2498 goto out;
2499
2500 /* Special hack: user can direct multicasts
2501 and limited broadcast via necessary interface
2502 without fiddling with IP_MULTICAST_IF or IP_PKTINFO.
2503 This hack is not just for fun, it allows
2504 vic,vat and friends to work.
2505 They bind socket to loopback, set ttl to zero
2506 and expect that it will work.
2507 From the viewpoint of routing cache they are broken,
2508 because we are not allowed to build multicast path
2509 with loopback source addr (look, routing cache
2510 cannot know, that ttl is zero, so that packet
2511 will not leave this host and route is valid).
2512 Luckily, this hack is good workaround.
2513 */
2514
2515 fl4->flowi4_oif = dev_out->ifindex;
2516 goto make_route;
2517 }
2518
2519 if (!(fl4->flowi4_flags & FLOWI_FLAG_ANYSRC)) {
2520 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */
2521 if (!__ip_dev_find(net, fl4->saddr, false))
2522 goto out;
2523 }
2524 }
2525
2526
2527 if (fl4->flowi4_oif) {
2528 dev_out = dev_get_by_index_rcu(net, fl4->flowi4_oif);
2529 rth = ERR_PTR(-ENODEV);
2530 if (dev_out == NULL)
2531 goto out;
2532
2533 /* RACE: Check return value of inet_select_addr instead. */
2534 if (!(dev_out->flags & IFF_UP) || !__in_dev_get_rcu(dev_out)) {
2535 rth = ERR_PTR(-ENETUNREACH);
2536 goto out;
2537 }
2538 if (ipv4_is_local_multicast(fl4->daddr) ||
2539 ipv4_is_lbcast(fl4->daddr)) {
2540 if (!fl4->saddr)
2541 fl4->saddr = inet_select_addr(dev_out, 0,
2542 RT_SCOPE_LINK);
2543 goto make_route;
2544 }
2545 if (fl4->saddr) {
2546 if (ipv4_is_multicast(fl4->daddr))
2547 fl4->saddr = inet_select_addr(dev_out, 0,
2548 fl4->flowi4_scope);
2549 else if (!fl4->daddr)
2550 fl4->saddr = inet_select_addr(dev_out, 0,
2551 RT_SCOPE_HOST);
2552 }
2553 }
2554
2555 if (!fl4->daddr) {
2556 fl4->daddr = fl4->saddr;
2557 if (!fl4->daddr)
2558 fl4->daddr = fl4->saddr = htonl(INADDR_LOOPBACK);
2559 dev_out = net->loopback_dev;
2560 fl4->flowi4_oif = net->loopback_dev->ifindex;
2561 res.type = RTN_LOCAL;
2562 flags |= RTCF_LOCAL;
2563 goto make_route;
2564 }
2565
2566 if (fib_lookup(net, fl4, &res)) {
2567 res.fi = NULL;
2568 if (fl4->flowi4_oif) {
2569 /* Apparently, routing tables are wrong. Assume,
2570 that the destination is on link.
2571
2572 WHY? DW.
2573 Because we are allowed to send to iface
2574 even if it has NO routes and NO assigned
2575 addresses. When oif is specified, routing
2576 tables are looked up with only one purpose:
2577 to catch if destination is gatewayed, rather than
2578 direct. Moreover, if MSG_DONTROUTE is set,
2579 we send packet, ignoring both routing tables
2580 and ifaddr state. --ANK
2581
2582
2583 We could make it even if oif is unknown,
2584 likely IPv6, but we do not.
2585 */
2586
2587 if (fl4->saddr == 0)
2588 fl4->saddr = inet_select_addr(dev_out, 0,
2589 RT_SCOPE_LINK);
2590 res.type = RTN_UNICAST;
2591 goto make_route;
2592 }
2593 rth = ERR_PTR(-ENETUNREACH);
2594 goto out;
2595 }
2596
2597 if (res.type == RTN_LOCAL) {
2598 if (!fl4->saddr) {
2599 if (res.fi->fib_prefsrc)
2600 fl4->saddr = res.fi->fib_prefsrc;
2601 else
2602 fl4->saddr = fl4->daddr;
2603 }
2604 dev_out = net->loopback_dev;
2605 fl4->flowi4_oif = dev_out->ifindex;
2606 res.fi = NULL;
2607 flags |= RTCF_LOCAL;
2608 goto make_route;
2609 }
2610
2611 #ifdef CONFIG_IP_ROUTE_MULTIPATH
2612 if (res.fi->fib_nhs > 1 && fl4->flowi4_oif == 0)
2613 fib_select_multipath(&res);
2614 else
2615 #endif
2616 if (!res.prefixlen &&
2617 res.table->tb_num_default > 1 &&
2618 res.type == RTN_UNICAST && !fl4->flowi4_oif)
2619 fib_select_default(&res);
2620
2621 if (!fl4->saddr)
2622 fl4->saddr = FIB_RES_PREFSRC(net, res);
2623
2624 dev_out = FIB_RES_DEV(res);
2625 fl4->flowi4_oif = dev_out->ifindex;
2626
2627
2628 make_route:
2629 rth = __mkroute_output(&res, fl4, orig_daddr, orig_saddr, orig_oif,
2630 dev_out, flags);
2631 if (!IS_ERR(rth)) {
2632 unsigned int hash;
2633
2634 hash = rt_hash(orig_daddr, orig_saddr, orig_oif,
2635 rt_genid(dev_net(dev_out)));
2636 rth = rt_intern_hash(hash, rth, NULL, orig_oif);
2637 }
2638
2639 out:
2640 rcu_read_unlock();
2641 return rth;
2642 }
2643
2644 struct rtable *__ip_route_output_key(struct net *net, struct flowi4 *flp4)
2645 {
2646 struct rtable *rth;
2647 unsigned int hash;
2648
2649 if (!rt_caching(net))
2650 goto slow_output;
2651
2652 hash = rt_hash(flp4->daddr, flp4->saddr, flp4->flowi4_oif, rt_genid(net));
2653
2654 rcu_read_lock_bh();
2655 for (rth = rcu_dereference_bh(rt_hash_table[hash].chain); rth;
2656 rth = rcu_dereference_bh(rth->dst.rt_next)) {
2657 if (rth->rt_key_dst == flp4->daddr &&
2658 rth->rt_key_src == flp4->saddr &&
2659 rt_is_output_route(rth) &&
2660 rth->rt_oif == flp4->flowi4_oif &&
2661 rth->rt_mark == flp4->flowi4_mark &&
2662 !((rth->rt_key_tos ^ flp4->flowi4_tos) &
2663 (IPTOS_RT_MASK | RTO_ONLINK)) &&
2664 net_eq(dev_net(rth->dst.dev), net) &&
2665 !rt_is_expired(rth)) {
2666 dst_use(&rth->dst, jiffies);
2667 RT_CACHE_STAT_INC(out_hit);
2668 rcu_read_unlock_bh();
2669 if (!flp4->saddr)
2670 flp4->saddr = rth->rt_src;
2671 if (!flp4->daddr)
2672 flp4->daddr = rth->rt_dst;
2673 return rth;
2674 }
2675 RT_CACHE_STAT_INC(out_hlist_search);
2676 }
2677 rcu_read_unlock_bh();
2678
2679 slow_output:
2680 return ip_route_output_slow(net, flp4);
2681 }
2682 EXPORT_SYMBOL_GPL(__ip_route_output_key);
2683
2684 static struct dst_entry *ipv4_blackhole_dst_check(struct dst_entry *dst, u32 cookie)
2685 {
2686 return NULL;
2687 }
2688
2689 static unsigned int ipv4_blackhole_default_mtu(const struct dst_entry *dst)
2690 {
2691 return 0;
2692 }
2693
2694 static void ipv4_rt_blackhole_update_pmtu(struct dst_entry *dst, u32 mtu)
2695 {
2696 }
2697
2698 static u32 *ipv4_rt_blackhole_cow_metrics(struct dst_entry *dst,
2699 unsigned long old)
2700 {
2701 return NULL;
2702 }
2703
2704 static struct dst_ops ipv4_dst_blackhole_ops = {
2705 .family = AF_INET,
2706 .protocol = cpu_to_be16(ETH_P_IP),
2707 .destroy = ipv4_dst_destroy,
2708 .check = ipv4_blackhole_dst_check,
2709 .default_mtu = ipv4_blackhole_default_mtu,
2710 .default_advmss = ipv4_default_advmss,
2711 .update_pmtu = ipv4_rt_blackhole_update_pmtu,
2712 .cow_metrics = ipv4_rt_blackhole_cow_metrics,
2713 };
2714
2715 struct dst_entry *ipv4_blackhole_route(struct net *net, struct dst_entry *dst_orig)
2716 {
2717 struct rtable *rt = dst_alloc(&ipv4_dst_blackhole_ops, NULL, 1, 0, 0);
2718 struct rtable *ort = (struct rtable *) dst_orig;
2719
2720 if (rt) {
2721 struct dst_entry *new = &rt->dst;
2722
2723 new->__use = 1;
2724 new->input = dst_discard;
2725 new->output = dst_discard;
2726 dst_copy_metrics(new, &ort->dst);
2727
2728 new->dev = ort->dst.dev;
2729 if (new->dev)
2730 dev_hold(new->dev);
2731
2732 rt->rt_key_dst = ort->rt_key_dst;
2733 rt->rt_key_src = ort->rt_key_src;
2734 rt->rt_key_tos = ort->rt_key_tos;
2735 rt->rt_route_iif = ort->rt_route_iif;
2736 rt->rt_iif = ort->rt_iif;
2737 rt->rt_oif = ort->rt_oif;
2738 rt->rt_mark = ort->rt_mark;
2739
2740 rt->rt_genid = rt_genid(net);
2741 rt->rt_flags = ort->rt_flags;
2742 rt->rt_type = ort->rt_type;
2743 rt->rt_dst = ort->rt_dst;
2744 rt->rt_src = ort->rt_src;
2745 rt->rt_gateway = ort->rt_gateway;
2746 rt->rt_spec_dst = ort->rt_spec_dst;
2747 rt->peer = ort->peer;
2748 if (rt->peer)
2749 atomic_inc(&rt->peer->refcnt);
2750 rt->fi = ort->fi;
2751 if (rt->fi)
2752 atomic_inc(&rt->fi->fib_clntref);
2753
2754 dst_free(new);
2755 }
2756
2757 dst_release(dst_orig);
2758
2759 return rt ? &rt->dst : ERR_PTR(-ENOMEM);
2760 }
2761
2762 struct rtable *ip_route_output_flow(struct net *net, struct flowi4 *flp4,
2763 struct sock *sk)
2764 {
2765 struct rtable *rt = __ip_route_output_key(net, flp4);
2766
2767 if (IS_ERR(rt))
2768 return rt;
2769
2770 if (flp4->flowi4_proto)
2771 rt = (struct rtable *) xfrm_lookup(net, &rt->dst,
2772 flowi4_to_flowi(flp4),
2773 sk, 0);
2774
2775 return rt;
2776 }
2777 EXPORT_SYMBOL_GPL(ip_route_output_flow);
2778
2779 static int rt_fill_info(struct net *net,
2780 struct sk_buff *skb, u32 pid, u32 seq, int event,
2781 int nowait, unsigned int flags)
2782 {
2783 struct rtable *rt = skb_rtable(skb);
2784 struct rtmsg *r;
2785 struct nlmsghdr *nlh;
2786 long expires = 0;
2787 const struct inet_peer *peer = rt->peer;
2788 u32 id = 0, ts = 0, tsage = 0, error;
2789
2790 nlh = nlmsg_put(skb, pid, seq, event, sizeof(*r), flags);
2791 if (nlh == NULL)
2792 return -EMSGSIZE;
2793
2794 r = nlmsg_data(nlh);
2795 r->rtm_family = AF_INET;
2796 r->rtm_dst_len = 32;
2797 r->rtm_src_len = 0;
2798 r->rtm_tos = rt->rt_key_tos;
2799 r->rtm_table = RT_TABLE_MAIN;
2800 NLA_PUT_U32(skb, RTA_TABLE, RT_TABLE_MAIN);
2801 r->rtm_type = rt->rt_type;
2802 r->rtm_scope = RT_SCOPE_UNIVERSE;
2803 r->rtm_protocol = RTPROT_UNSPEC;
2804 r->rtm_flags = (rt->rt_flags & ~0xFFFF) | RTM_F_CLONED;
2805 if (rt->rt_flags & RTCF_NOTIFY)
2806 r->rtm_flags |= RTM_F_NOTIFY;
2807
2808 NLA_PUT_BE32(skb, RTA_DST, rt->rt_dst);
2809
2810 if (rt->rt_key_src) {
2811 r->rtm_src_len = 32;
2812 NLA_PUT_BE32(skb, RTA_SRC, rt->rt_key_src);
2813 }
2814 if (rt->dst.dev)
2815 NLA_PUT_U32(skb, RTA_OIF, rt->dst.dev->ifindex);
2816 #ifdef CONFIG_IP_ROUTE_CLASSID
2817 if (rt->dst.tclassid)
2818 NLA_PUT_U32(skb, RTA_FLOW, rt->dst.tclassid);
2819 #endif
2820 if (rt_is_input_route(rt))
2821 NLA_PUT_BE32(skb, RTA_PREFSRC, rt->rt_spec_dst);
2822 else if (rt->rt_src != rt->rt_key_src)
2823 NLA_PUT_BE32(skb, RTA_PREFSRC, rt->rt_src);
2824
2825 if (rt->rt_dst != rt->rt_gateway)
2826 NLA_PUT_BE32(skb, RTA_GATEWAY, rt->rt_gateway);
2827
2828 if (rtnetlink_put_metrics(skb, dst_metrics_ptr(&rt->dst)) < 0)
2829 goto nla_put_failure;
2830
2831 if (rt->rt_mark)
2832 NLA_PUT_BE32(skb, RTA_MARK, rt->rt_mark);
2833
2834 error = rt->dst.error;
2835 if (peer) {
2836 inet_peer_refcheck(rt->peer);
2837 id = atomic_read(&peer->ip_id_count) & 0xffff;
2838 if (peer->tcp_ts_stamp) {
2839 ts = peer->tcp_ts;
2840 tsage = get_seconds() - peer->tcp_ts_stamp;
2841 }
2842 expires = ACCESS_ONCE(peer->pmtu_expires);
2843 if (expires)
2844 expires -= jiffies;
2845 }
2846
2847 if (rt_is_input_route(rt)) {
2848 #ifdef CONFIG_IP_MROUTE
2849 __be32 dst = rt->rt_dst;
2850
2851 if (ipv4_is_multicast(dst) && !ipv4_is_local_multicast(dst) &&
2852 IPV4_DEVCONF_ALL(net, MC_FORWARDING)) {
2853 int err = ipmr_get_route(net, skb,
2854 rt->rt_src, rt->rt_dst,
2855 r, nowait);
2856 if (err <= 0) {
2857 if (!nowait) {
2858 if (err == 0)
2859 return 0;
2860 goto nla_put_failure;
2861 } else {
2862 if (err == -EMSGSIZE)
2863 goto nla_put_failure;
2864 error = err;
2865 }
2866 }
2867 } else
2868 #endif
2869 NLA_PUT_U32(skb, RTA_IIF, rt->rt_iif);
2870 }
2871
2872 if (rtnl_put_cacheinfo(skb, &rt->dst, id, ts, tsage,
2873 expires, error) < 0)
2874 goto nla_put_failure;
2875
2876 return nlmsg_end(skb, nlh);
2877
2878 nla_put_failure:
2879 nlmsg_cancel(skb, nlh);
2880 return -EMSGSIZE;
2881 }
2882
2883 static int inet_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr* nlh, void *arg)
2884 {
2885 struct net *net = sock_net(in_skb->sk);
2886 struct rtmsg *rtm;
2887 struct nlattr *tb[RTA_MAX+1];
2888 struct rtable *rt = NULL;
2889 __be32 dst = 0;
2890 __be32 src = 0;
2891 u32 iif;
2892 int err;
2893 int mark;
2894 struct sk_buff *skb;
2895
2896 err = nlmsg_parse(nlh, sizeof(*rtm), tb, RTA_MAX, rtm_ipv4_policy);
2897 if (err < 0)
2898 goto errout;
2899
2900 rtm = nlmsg_data(nlh);
2901
2902 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
2903 if (skb == NULL) {
2904 err = -ENOBUFS;
2905 goto errout;
2906 }
2907
2908 /* Reserve room for dummy headers, this skb can pass
2909 through good chunk of routing engine.
2910 */
2911 skb_reset_mac_header(skb);
2912 skb_reset_network_header(skb);
2913
2914 /* Bugfix: need to give ip_route_input enough of an IP header to not gag. */
2915 ip_hdr(skb)->protocol = IPPROTO_ICMP;
2916 skb_reserve(skb, MAX_HEADER + sizeof(struct iphdr));
2917
2918 src = tb[RTA_SRC] ? nla_get_be32(tb[RTA_SRC]) : 0;
2919 dst = tb[RTA_DST] ? nla_get_be32(tb[RTA_DST]) : 0;
2920 iif = tb[RTA_IIF] ? nla_get_u32(tb[RTA_IIF]) : 0;
2921 mark = tb[RTA_MARK] ? nla_get_u32(tb[RTA_MARK]) : 0;
2922
2923 if (iif) {
2924 struct net_device *dev;
2925
2926 dev = __dev_get_by_index(net, iif);
2927 if (dev == NULL) {
2928 err = -ENODEV;
2929 goto errout_free;
2930 }
2931
2932 skb->protocol = htons(ETH_P_IP);
2933 skb->dev = dev;
2934 skb->mark = mark;
2935 local_bh_disable();
2936 err = ip_route_input(skb, dst, src, rtm->rtm_tos, dev);
2937 local_bh_enable();
2938
2939 rt = skb_rtable(skb);
2940 if (err == 0 && rt->dst.error)
2941 err = -rt->dst.error;
2942 } else {
2943 struct flowi4 fl4 = {
2944 .daddr = dst,
2945 .saddr = src,
2946 .flowi4_tos = rtm->rtm_tos,
2947 .flowi4_oif = tb[RTA_OIF] ? nla_get_u32(tb[RTA_OIF]) : 0,
2948 .flowi4_mark = mark,
2949 };
2950 rt = ip_route_output_key(net, &fl4);
2951
2952 err = 0;
2953 if (IS_ERR(rt))
2954 err = PTR_ERR(rt);
2955 }
2956
2957 if (err)
2958 goto errout_free;
2959
2960 skb_dst_set(skb, &rt->dst);
2961 if (rtm->rtm_flags & RTM_F_NOTIFY)
2962 rt->rt_flags |= RTCF_NOTIFY;
2963
2964 err = rt_fill_info(net, skb, NETLINK_CB(in_skb).pid, nlh->nlmsg_seq,
2965 RTM_NEWROUTE, 0, 0);
2966 if (err <= 0)
2967 goto errout_free;
2968
2969 err = rtnl_unicast(skb, net, NETLINK_CB(in_skb).pid);
2970 errout:
2971 return err;
2972
2973 errout_free:
2974 kfree_skb(skb);
2975 goto errout;
2976 }
2977
2978 int ip_rt_dump(struct sk_buff *skb, struct netlink_callback *cb)
2979 {
2980 struct rtable *rt;
2981 int h, s_h;
2982 int idx, s_idx;
2983 struct net *net;
2984
2985 net = sock_net(skb->sk);
2986
2987 s_h = cb->args[0];
2988 if (s_h < 0)
2989 s_h = 0;
2990 s_idx = idx = cb->args[1];
2991 for (h = s_h; h <= rt_hash_mask; h++, s_idx = 0) {
2992 if (!rt_hash_table[h].chain)
2993 continue;
2994 rcu_read_lock_bh();
2995 for (rt = rcu_dereference_bh(rt_hash_table[h].chain), idx = 0; rt;
2996 rt = rcu_dereference_bh(rt->dst.rt_next), idx++) {
2997 if (!net_eq(dev_net(rt->dst.dev), net) || idx < s_idx)
2998 continue;
2999 if (rt_is_expired(rt))
3000 continue;
3001 skb_dst_set_noref(skb, &rt->dst);
3002 if (rt_fill_info(net, skb, NETLINK_CB(cb->skb).pid,
3003 cb->nlh->nlmsg_seq, RTM_NEWROUTE,
3004 1, NLM_F_MULTI) <= 0) {
3005 skb_dst_drop(skb);
3006 rcu_read_unlock_bh();
3007 goto done;
3008 }
3009 skb_dst_drop(skb);
3010 }
3011 rcu_read_unlock_bh();
3012 }
3013
3014 done:
3015 cb->args[0] = h;
3016 cb->args[1] = idx;
3017 return skb->len;
3018 }
3019
3020 void ip_rt_multicast_event(struct in_device *in_dev)
3021 {
3022 rt_cache_flush(dev_net(in_dev->dev), 0);
3023 }
3024
3025 #ifdef CONFIG_SYSCTL
3026 static int ipv4_sysctl_rtcache_flush(ctl_table *__ctl, int write,
3027 void __user *buffer,
3028 size_t *lenp, loff_t *ppos)
3029 {
3030 if (write) {
3031 int flush_delay;
3032 ctl_table ctl;
3033 struct net *net;
3034
3035 memcpy(&ctl, __ctl, sizeof(ctl));
3036 ctl.data = &flush_delay;
3037 proc_dointvec(&ctl, write, buffer, lenp, ppos);
3038
3039 net = (struct net *)__ctl->extra1;
3040 rt_cache_flush(net, flush_delay);
3041 return 0;
3042 }
3043
3044 return -EINVAL;
3045 }
3046
3047 static ctl_table ipv4_route_table[] = {
3048 {
3049 .procname = "gc_thresh",
3050 .data = &ipv4_dst_ops.gc_thresh,
3051 .maxlen = sizeof(int),
3052 .mode = 0644,
3053 .proc_handler = proc_dointvec,
3054 },
3055 {
3056 .procname = "max_size",
3057 .data = &ip_rt_max_size,
3058 .maxlen = sizeof(int),
3059 .mode = 0644,
3060 .proc_handler = proc_dointvec,
3061 },
3062 {
3063 /* Deprecated. Use gc_min_interval_ms */
3064
3065 .procname = "gc_min_interval",
3066 .data = &ip_rt_gc_min_interval,
3067 .maxlen = sizeof(int),
3068 .mode = 0644,
3069 .proc_handler = proc_dointvec_jiffies,
3070 },
3071 {
3072 .procname = "gc_min_interval_ms",
3073 .data = &ip_rt_gc_min_interval,
3074 .maxlen = sizeof(int),
3075 .mode = 0644,
3076 .proc_handler = proc_dointvec_ms_jiffies,
3077 },
3078 {
3079 .procname = "gc_timeout",
3080 .data = &ip_rt_gc_timeout,
3081 .maxlen = sizeof(int),
3082 .mode = 0644,
3083 .proc_handler = proc_dointvec_jiffies,
3084 },
3085 {
3086 .procname = "gc_interval",
3087 .data = &ip_rt_gc_interval,
3088 .maxlen = sizeof(int),
3089 .mode = 0644,
3090 .proc_handler = proc_dointvec_jiffies,
3091 },
3092 {
3093 .procname = "redirect_load",
3094 .data = &ip_rt_redirect_load,
3095 .maxlen = sizeof(int),
3096 .mode = 0644,
3097 .proc_handler = proc_dointvec,
3098 },
3099 {
3100 .procname = "redirect_number",
3101 .data = &ip_rt_redirect_number,
3102 .maxlen = sizeof(int),
3103 .mode = 0644,
3104 .proc_handler = proc_dointvec,
3105 },
3106 {
3107 .procname = "redirect_silence",
3108 .data = &ip_rt_redirect_silence,
3109 .maxlen = sizeof(int),
3110 .mode = 0644,
3111 .proc_handler = proc_dointvec,
3112 },
3113 {
3114 .procname = "error_cost",
3115 .data = &ip_rt_error_cost,
3116 .maxlen = sizeof(int),
3117 .mode = 0644,
3118 .proc_handler = proc_dointvec,
3119 },
3120 {
3121 .procname = "error_burst",
3122 .data = &ip_rt_error_burst,
3123 .maxlen = sizeof(int),
3124 .mode = 0644,
3125 .proc_handler = proc_dointvec,
3126 },
3127 {
3128 .procname = "gc_elasticity",
3129 .data = &ip_rt_gc_elasticity,
3130 .maxlen = sizeof(int),
3131 .mode = 0644,
3132 .proc_handler = proc_dointvec,
3133 },
3134 {
3135 .procname = "mtu_expires",
3136 .data = &ip_rt_mtu_expires,
3137 .maxlen = sizeof(int),
3138 .mode = 0644,
3139 .proc_handler = proc_dointvec_jiffies,
3140 },
3141 {
3142 .procname = "min_pmtu",
3143 .data = &ip_rt_min_pmtu,
3144 .maxlen = sizeof(int),
3145 .mode = 0644,
3146 .proc_handler = proc_dointvec,
3147 },
3148 {
3149 .procname = "min_adv_mss",
3150 .data = &ip_rt_min_advmss,
3151 .maxlen = sizeof(int),
3152 .mode = 0644,
3153 .proc_handler = proc_dointvec,
3154 },
3155 { }
3156 };
3157
3158 static struct ctl_table empty[1];
3159
3160 static struct ctl_table ipv4_skeleton[] =
3161 {
3162 { .procname = "route",
3163 .mode = 0555, .child = ipv4_route_table},
3164 { .procname = "neigh",
3165 .mode = 0555, .child = empty},
3166 { }
3167 };
3168
3169 static __net_initdata struct ctl_path ipv4_path[] = {
3170 { .procname = "net", },
3171 { .procname = "ipv4", },
3172 { },
3173 };
3174
3175 static struct ctl_table ipv4_route_flush_table[] = {
3176 {
3177 .procname = "flush",
3178 .maxlen = sizeof(int),
3179 .mode = 0200,
3180 .proc_handler = ipv4_sysctl_rtcache_flush,
3181 },
3182 { },
3183 };
3184
3185 static __net_initdata struct ctl_path ipv4_route_path[] = {
3186 { .procname = "net", },
3187 { .procname = "ipv4", },
3188 { .procname = "route", },
3189 { },
3190 };
3191
3192 static __net_init int sysctl_route_net_init(struct net *net)
3193 {
3194 struct ctl_table *tbl;
3195
3196 tbl = ipv4_route_flush_table;
3197 if (!net_eq(net, &init_net)) {
3198 tbl = kmemdup(tbl, sizeof(ipv4_route_flush_table), GFP_KERNEL);
3199 if (tbl == NULL)
3200 goto err_dup;
3201 }
3202 tbl[0].extra1 = net;
3203
3204 net->ipv4.route_hdr =
3205 register_net_sysctl_table(net, ipv4_route_path, tbl);
3206 if (net->ipv4.route_hdr == NULL)
3207 goto err_reg;
3208 return 0;
3209
3210 err_reg:
3211 if (tbl != ipv4_route_flush_table)
3212 kfree(tbl);
3213 err_dup:
3214 return -ENOMEM;
3215 }
3216
3217 static __net_exit void sysctl_route_net_exit(struct net *net)
3218 {
3219 struct ctl_table *tbl;
3220
3221 tbl = net->ipv4.route_hdr->ctl_table_arg;
3222 unregister_net_sysctl_table(net->ipv4.route_hdr);
3223 BUG_ON(tbl == ipv4_route_flush_table);
3224 kfree(tbl);
3225 }
3226
3227 static __net_initdata struct pernet_operations sysctl_route_ops = {
3228 .init = sysctl_route_net_init,
3229 .exit = sysctl_route_net_exit,
3230 };
3231 #endif
3232
3233 static __net_init int rt_genid_init(struct net *net)
3234 {
3235 get_random_bytes(&net->ipv4.rt_genid,
3236 sizeof(net->ipv4.rt_genid));
3237 get_random_bytes(&net->ipv4.dev_addr_genid,
3238 sizeof(net->ipv4.dev_addr_genid));
3239 return 0;
3240 }
3241
3242 static __net_initdata struct pernet_operations rt_genid_ops = {
3243 .init = rt_genid_init,
3244 };
3245
3246
3247 #ifdef CONFIG_IP_ROUTE_CLASSID
3248 struct ip_rt_acct __percpu *ip_rt_acct __read_mostly;
3249 #endif /* CONFIG_IP_ROUTE_CLASSID */
3250
3251 static __initdata unsigned long rhash_entries;
3252 static int __init set_rhash_entries(char *str)
3253 {
3254 if (!str)
3255 return 0;
3256 rhash_entries = simple_strtoul(str, &str, 0);
3257 return 1;
3258 }
3259 __setup("rhash_entries=", set_rhash_entries);
3260
3261 int __init ip_rt_init(void)
3262 {
3263 int rc = 0;
3264
3265 #ifdef CONFIG_IP_ROUTE_CLASSID
3266 ip_rt_acct = __alloc_percpu(256 * sizeof(struct ip_rt_acct), __alignof__(struct ip_rt_acct));
3267 if (!ip_rt_acct)
3268 panic("IP: failed to allocate ip_rt_acct\n");
3269 #endif
3270
3271 ipv4_dst_ops.kmem_cachep =
3272 kmem_cache_create("ip_dst_cache", sizeof(struct rtable), 0,
3273 SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL);
3274
3275 ipv4_dst_blackhole_ops.kmem_cachep = ipv4_dst_ops.kmem_cachep;
3276
3277 if (dst_entries_init(&ipv4_dst_ops) < 0)
3278 panic("IP: failed to allocate ipv4_dst_ops counter\n");
3279
3280 if (dst_entries_init(&ipv4_dst_blackhole_ops) < 0)
3281 panic("IP: failed to allocate ipv4_dst_blackhole_ops counter\n");
3282
3283 rt_hash_table = (struct rt_hash_bucket *)
3284 alloc_large_system_hash("IP route cache",
3285 sizeof(struct rt_hash_bucket),
3286 rhash_entries,
3287 (totalram_pages >= 128 * 1024) ?
3288 15 : 17,
3289 0,
3290 &rt_hash_log,
3291 &rt_hash_mask,
3292 rhash_entries ? 0 : 512 * 1024);
3293 memset(rt_hash_table, 0, (rt_hash_mask + 1) * sizeof(struct rt_hash_bucket));
3294 rt_hash_lock_init();
3295
3296 ipv4_dst_ops.gc_thresh = (rt_hash_mask + 1);
3297 ip_rt_max_size = (rt_hash_mask + 1) * 16;
3298
3299 devinet_init();
3300 ip_fib_init();
3301
3302 if (ip_rt_proc_init())
3303 printk(KERN_ERR "Unable to create route proc files\n");
3304 #ifdef CONFIG_XFRM
3305 xfrm_init();
3306 xfrm4_init(ip_rt_max_size);
3307 #endif
3308 rtnl_register(PF_INET, RTM_GETROUTE, inet_rtm_getroute, NULL);
3309
3310 #ifdef CONFIG_SYSCTL
3311 register_pernet_subsys(&sysctl_route_ops);
3312 #endif
3313 register_pernet_subsys(&rt_genid_ops);
3314 return rc;
3315 }
3316
3317 #ifdef CONFIG_SYSCTL
3318 /*
3319 * We really need to sanitize the damn ipv4 init order, then all
3320 * this nonsense will go away.
3321 */
3322 void __init ip_static_sysctl_init(void)
3323 {
3324 register_sysctl_paths(ipv4_path, ipv4_skeleton);
3325 }
3326 #endif
Linux 2.6 ibm-acpi/thinkpad-acpi driver git tree